miniupnpd creates invalid firewall entries

[gbruns]

Hi there,

I noticed after a reboot of my (gentoo) router that the firewall was broken.
Reason was an entry like that "-A MINIUPNPD -p udp -m udp --dport 12345 -j DNAT [unsupported revision]" in /var/lib/iptables/rules-save.
The entry was created by miniupnpd when a client requested a port forward.

I searched the internet but don't found any solution to the problem.
Ppl suggesting to switch to nft or at least to iptables on top of nft.
I tried that but all my firewall rules were lost and miniupnpd doesn't even work. So before I put more time in switching to nft maybe someone has an idea.

I am using gentoo-sources-5.4.254, iptables-1.8.9 and miniupnpd-2.3.3.
Miniupnpd is a binary and uses iptc_ functions from iptables (libiptc) to modify the firewall afaik.

regards
Goeran