Dumb AP: Wifi with VLANs not working

I have a OpenWRT AP with one Ethernet Port.
It has configured VLAN 10 for guest ethernet (wifi ssid "Gast") and VLAN 1 for private ethernet (wifi ssid "WLAN OlCa").
I can connect from private ethernet over Cable to the AP and the AP has also internet access (ping 1.1.1.1 is working)
For VLAN 1 and VLAN 10 there is an DHCP Server in the network (different IP ranges).

If I have no VLAN configured, the private wifi is working well (with DHCP and internet access)
But if I activate VLANs, only cable connection to the AP is working.

But over wifi (private and guest) there is no access to the DHCP Server or the internet.

So I guess, there is any misconfiguration at the AP.

/etc/config/network

config interface 'loopback'
        option device 'lo'
        option proto 'static'
        option ipaddr '127.0.0.1'
        option netmask '255.0.0.0'

config globals 'globals'
        option ula_prefix 'fd71:f3c8:c98e::/48'

config device
        option name 'br-lan'
        option type 'bridge'
        list ports 'eth0'

config interface 'lan'
        option device 'br-lan.1'
        option proto 'static'
        option ipaddr '192.168.178.18'
        option netmask '255.255.255.0'
        option ip6assign '60'
        option gateway '192.168.178.1'
        list dns '192.168.178.1'

config interface 'Gast'
        option proto 'none'
        option device 'br-lan.10'

config bridge-vlan
        option device 'br-lan'
        option vlan '1'
        list ports 'eth0:u*'

config bridge-vlan
        option device 'br-lan'
        option vlan '10'
        list ports 'eth0:t'

/etc/config/wireless

config wifi-device 'radio0'
        option type 'mac80211'
        option path 'pci0000:00/0000:00:00.0'
        option channel '36'
        option band '5g'
        option htmode 'VHT80'
        option cell_density '0'

config wifi-device 'radio1'
        option type 'mac80211'
        option path 'platform/ahb/18100000.wmac'
        option channel '1'
        option band '2g'
        option htmode 'HT20'
        option cell_density '0'

config wifi-iface 'wifinet0'
        option device 'radio0'
        option mode 'ap'
        option ssid 'WLAN OlCa'
        option encryption 'psk2'
        option key '------'
        option network 'lan'

config wifi-iface 'wifinet1'
        option device 'radio1'
        option mode 'ap'
        option ssid 'WLAN OlCa'
        option encryption 'psk2'
        option key '-----'
        option network 'lan'

config wifi-iface 'wifinet2'
        option device 'radio0'
        option mode 'ap'
        option ssid 'Gast'
        option encryption 'psk2'
        option key '-----'
        option network 'Gast'

config wifi-iface 'wifinet3'
        option device 'radio1'
        option mode 'ap'
        option ssid 'Gast'
        option encryption 'psk2'
        option key '------'
        option network 'Gast'

/etc/config/firewall

config defaults
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'ACCEPT'
        option synflood_protect '1'

config zone
        option name 'lan'
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'ACCEPT'
        list network 'lan'

config zone
        option name 'wan'
        list network 'wan'
        list network 'wan6'
        option input 'REJECT'
        option output 'ACCEPT'
        option forward 'REJECT'
        option masq '1'
        option mtu_fix '1'

config forwarding
        option src 'lan'
        option dest 'wan'

config rule
        option name 'Allow-DHCP-Renew'
        option src 'wan'
        option proto 'udp'
        option dest_port '68'
        option target 'ACCEPT'
        option family 'ipv4'

config rule
        option name 'Allow-Ping'
        option src 'wan'
        option proto 'icmp'
        option icmp_type 'echo-request'
        option family 'ipv4'
        option target 'ACCEPT'

config rule
        option name 'Allow-IGMP'
        option src 'wan'
        option proto 'igmp'
        option family 'ipv4'
        option target 'ACCEPT'

config rule
        option name 'Allow-DHCPv6'
        option src 'wan'
        option proto 'udp'
        option dest_port '546'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-MLD'
        option src 'wan'
        option proto 'icmp'
        option src_ip 'fe80::/10'
        list icmp_type '130/0'
        list icmp_type '131/0'
        list icmp_type '132/0'
        list icmp_type '143/0'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-ICMPv6-Input'
        option src 'wan'
        option proto 'icmp'
        list icmp_type 'echo-request'
        list icmp_type 'echo-reply'
        list icmp_type 'destination-unreachable'
        list icmp_type 'packet-too-big'
        list icmp_type 'time-exceeded'
        list icmp_type 'bad-header'
        list icmp_type 'unknown-header-type'
        list icmp_type 'router-solicitation'
        list icmp_type 'neighbour-solicitation'
        list icmp_type 'router-advertisement'
        list icmp_type 'neighbour-advertisement'
        option limit '1000/sec'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-ICMPv6-Forward'
        option src 'wan'
        option dest '*'
        option proto 'icmp'
        list icmp_type 'echo-request'
        list icmp_type 'echo-reply'
        list icmp_type 'destination-unreachable'
        list icmp_type 'packet-too-big'
        list icmp_type 'time-exceeded'
        list icmp_type 'bad-header'
        list icmp_type 'unknown-header-type'
        option limit '1000/sec'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-IPSec-ESP'
        option src 'wan'
        option dest 'lan'
        option proto 'esp'
        option target 'ACCEPT'

config rule
        option name 'Allow-ISAKMP'
        option src 'wan'
        option dest 'lan'
        option dest_port '500'
        option proto 'udp'
        option target 'ACCEPT'

config zone
        option name 'Gast'
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'ACCEPT'
        list network 'Gast'

config forwarding
        option src 'Gast'
        option dest 'lan'

/etc/config/dhcp

config dnsmasq
        option domainneeded '1'
        option boguspriv '1'
        option filterwin2k '0'
        option localise_queries '1'
        option rebind_protection '1'
        option rebind_localhost '1'
        option local '/lan/'
        option domain 'lan'
        option expandhosts '1'
        option nonegcache '0'
        option cachesize '1000'
        option authoritative '1'
        option readethers '1'
        option leasefile '/tmp/dhcp.leases'
        option resolvfile '/tmp/resolv.conf.d/resolv.conf.auto'
        option nonwildcard '1'
        option localservice '1'
        option ednspacket_max '1232'
        option filter_aaaa '0'
        option filter_a '0'

config dhcp 'lan'
        option interface 'lan'
        option start '100'
        option limit '150'
        option leasetime '12h'
        option dhcpv4 'server'
        option dhcpv6 'server'
        option ra 'server'
        list ra_flags 'managed-config'
        list ra_flags 'other-config'
        option ignore '1'

config dhcp 'wan'
        option interface 'wan'
        option ignore '1'

config odhcpd 'odhcpd'
        option maindhcp '0'
        option leasefile '/tmp/hosts/odhcpd'
        option leasetrigger '/usr/sbin/odhcpd-update'
        option loglevel '4'

config dhcp 'Gast'
        option interface 'Gast'
        option start '100'
        option limit '150'
        option leasetime '12h'
        option ignore '1'

What is upstream of this AP? Is it a managed switch? or a router? Have you proven that the upstream ethernet is working as expected for both VLANs?

What is the device in question?

ubus call system board

This stuff in the firewall is not necessary (it's not causing any issues, but delete it because it's not needed):

Same for this:

Hello,

thanks for answering my question.

Here is the output of

ubus call system board

{
        "kernel": "5.15.134",
        "hostname": "OpenWrt",
        "system": "Qualcomm Atheros QCA956X ver 1 rev 0",
        "model": "Ubiquiti UniFi AC Lite",
        "board_name": "ubnt,unifiac-lite",
        "rootfs_type": "squashfs",
        "release": {
                "distribution": "OpenWrt",
                "version": "23.05.0",
                "revision": "r23497-6637af95aa",
                "target": "ath79/generic",
                "description": "OpenWrt 23.05.0 r23497-6637af95aa"
        }
}

But in time between I got my problem solved by myself.
I found many topics, where the interface has to be "unmanaged", but I thought this has only to be the second interface for tagged VLAN.

Now I added an other unmanaged interface (one for VLAN 1 and one for VLAN 10)

The wifis are connedted to these unmanaged interfaces and everything is working!

Here my woking config, maybe someone can use ist:

/etc/config/network

config interface 'loopback'
        option device 'lo'
        option proto 'static'
        option ipaddr '127.0.0.1'
        option netmask '255.0.0.0'

config globals 'globals'
        option ula_prefix 'fd71:f3c8:c98e::/48'

config device
        option name 'br-lan'
        option type 'bridge'
        list ports 'eth0'

config interface 'lan'
        option device 'br-lan.1'
        option proto 'static'
        option ipaddr '192.168.178.18'
        option netmask '255.255.255.0'
        option ip6assign '60'
        option gateway '192.168.178.1'
        list dns '192.168.178.1'

config interface 'Gast'
        option proto 'none'
        option device 'br-lan.10'

config bridge-vlan
        option device 'br-lan'
        option vlan '1'
        list ports 'eth0:u*'

config bridge-vlan
        option device 'br-lan'
        option vlan '10'
        list ports 'eth0:t'

config interface 'Privat'
        option proto 'none'
        option device 'br-lan.1'

/etc/config/wireless

config wifi-device 'radio0'
        option type 'mac80211'
        option path 'pci0000:00/0000:00:00.0'
        option channel '36'
        option band '5g'
        option htmode 'VHT80'
        option cell_density '0'

config wifi-device 'radio1'
        option type 'mac80211'
        option path 'platform/ahb/18100000.wmac'
        option channel '1'
        option band '2g'
        option htmode 'HT20'
        option cell_density '0'

config wifi-iface 'wifinet0'
        option device 'radio0'
        option mode 'ap'
        option ssid 'Gast'
        option encryption 'psk2'
        option key '------'
        option network 'Gast'

config wifi-iface 'wifinet1'
        option device 'radio1'
        option mode 'ap'
        option ssid 'Gast'
        option encryption 'psk2'
        option key '-----'
        option network 'Gast'

config wifi-iface 'wifinet2'
        option device 'radio0'
        option mode 'ap'
        option ssid 'WLAN OlCa'
        option encryption 'psk2'
        option key '-----'
        option network 'Privat'

config wifi-iface 'wifinet3'
        option device 'radio1'
        option mode 'ap'
        option ssid 'WLAN OlCa'
        option encryption 'psk2'
        option key '-----'
        option network 'Privat'