Upnp receives requests, then nothing happens

Hi,
I have OpenWrt 19.07.7 on linksys EA8500 dual stack IPv4 and IPv6 (native) bridged to a openwrt modem. Everything working fine from that POV.

However, I cannot get uPNP to work.

I was using miniupnpd, couldn't get it working, to swapped to miniupnpd-igdv1 - both behave exactly the same, neither work.

With debug log it appears that the daemon is receiving requests from LAN devices (windows 10PCs), but then... ignoring them? I don't know, there's no attempt to open a port or error messages...

Mon Apr 26 04:17:20 2021 daemon.debug miniupnpd[3064]: level=0 type=8
Mon Apr 26 04:17:20 2021 daemon.debug miniupnpd[3064]: ifindex = 7  192.168.2.1
Mon Apr 26 04:17:21 2021 daemon.debug miniupnpd[3064]: level=0 type=8
Mon Apr 26 04:17:21 2021 daemon.debug miniupnpd[3064]: ifindex = 7  192.168.2.1
Mon Apr 26 04:17:21 2021 daemon.debug miniupnpd[3064]: ST: upnp:rootdevice (ver=0)
Mon Apr 26 04:17:21 2021 daemon.info miniupnpd[3064]: SSDP M-SEARCH from 192.168.2.3:64735 ST: upnp:rootdevice
Mon Apr 26 04:17:21 2021 daemon.info miniupnpd[3064]: Single search found
 CONFIGID.UPNP.ORG: 13379935rg/upnp/1/0/"; ns=01.1pnp:rootdeviceesponse(): 0 bytes to 192.168.2.3:64735 ST: HTTP/1.1 200 OK

that's it. No redirects happen.

My config is:

config upnpd 'config'
	option download '1024'
	option upload '512'
	option external_iface 'wan4'
	option internal_iface 'lan'
	option port '5000'
	option upnp_lease_file '/var/run/miniupnpd.leases'
	option igdv1 '1'
	option ext_ip_reserved_ignore '1'
	option ipv6_disable '1'
	option enabled '1'
	option uuid '5dd3ed13-dcc1-4819-9770-b0d68aaceb76'
	option log_output '1'

config perm_rule
	option action 'allow'
	option ext_ports '1024-65535'
	option int_addr '0.0.0.0/0'
	option int_ports '1024-65535'
	option comment 'Allow high ports'

config perm_rule
	option action 'deny'
	option ext_ports '0-65535'
	option int_addr '0.0.0.0/0'
	option int_ports '0-65535'
	option comment 'Default deny'

Has exact same behaviour with default config (i.e. enabling IPv6 support too)

my network and firewall configs are basically default, nothing special

Any thoughts please?

that's the exact use case ?