2 ISP, 2 subnets and allowing devices to talk to each other

[quietsoviet]

So i have problem with configuring 2 home networks.
My parents house has Fritzbox ISP router with 192.168.0.0 IP range and i have ISP router in bridge mode with OpenWRT One serving as router on 192.168.1.0 IP range. I want to allow these 2 to talk to each other. So i tried by puting another openwrt router( GL.iNET MT300N or Mango) via ethernet to fritzbox with static address and connected it through 802.11s with my network. I can access mango from my network and from parents network, but i cant access cross network devices. So what can i do is it even doable? I dont need to share internet between them, i need to access some of their devices and they can access some of my.
This is mango settings
/etc/config/firewall

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



config zone
        option name 'lan'
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'ACCEPT'
        list network 'lan65'
        list network 'lan63'

/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 'fdfa:2c1:337b::/48'
        option packet_steering '1'

config switch
        option name 'switch0'
        option reset '1'
        option enable_vlan '1'

config switch_vlan
        option device 'switch0'
        option vlan '1'
        option ports '1 6t'

config switch_vlan
        option device 'switch0'
        option vlan '2'
        option ports '0 6t'

config interface 'lan65'
        option proto 'static'
        option device 'br-lan65'
        option ipaddr '192.168.1.138'
        option netmask '255.255.255.0'
        option gateway '192.168.1.1'
        list dns '8.8.8.8'

config device
        option type 'bridge'
        option name 'br-lan65'
        option ipv6 '0'

config device
        option type 'bridge'
        option name 'br-lan63'
        list ports 'eth0.1'
        option ipv6 '0'

config interface 'lan63'
        option proto 'static'
        option device 'br-lan63'
        option ipaddr '192.168.0.138'
        option netmask '255.255.255.0'

/etc/config/wireless

config wifi-device 'radio0'
        option type 'mac80211'
        option path 'platform/10300000.wmac'
        option band '2g'
        option channel '1'
        option htmode 'HT40'
        option country 'HR'
        option cell_density '0'

config wifi-iface 'default_radio0'
        option device 'radio0'
        option network 'lan65'
        option mode 'mesh'
        option encryption 'sae'
        option mesh_id 'cm'
        option mesh_fwding '1'
        option mesh_rssi_threshold '0'
        option key '*'

They are both in the same firewall zone. So is doable and what am i missing? Or is there any other why to make it work?

[slh]

You would need to define routes (on the F!B) and firewall settings. But recent'ish Fritz!OS versions have gained native wireguard support, which should make your endeavour easier (one fewer moving part to keep track of).

[quietsoviet]

@slh

r easier (one fewer moving part to

Thank you for you answer i did by routing, and let me tell you, there needs to be easier guide.