Some time ago, with core 161 I tested a mail server in my network and port forwarding was working well for all the port that it needed.
Now with core 162 I can not forward port 80, testing with nginx server in Xubuntu 20.04. I asked to my isp if they were using cg-nat and the answer was No. But after some reboots of ipfire to change the public IP (sometimes this fix the problem with my isp) the problem remains.
If they don’t use cg-nat, what I’m doing wrong?