bitcomet port forwarding issue

[A Former User]

Since 2 days or so I can no longer seed torrents (from this site). I could seed even so the seeding decreased massively down to bytes.
I have a ~15 MB download Internet connection (when downloading).

No matter what listen port I use in Bitcomet it always shows that the port is not working (banned). I did port forwarding in my router, but still no solution. I opened port in my router with the many many Bitcomet port numbers tried.

I would like to know if there are some important things to do (in router and Bitcomet).

I have Kaspersky firewall/anti-virus software. Windows Firewall and Windows Defender (or what else) are never activated (always blocked/disabled).

Are there important port numbers (like 64500) that (should) work with Bitcomet? I am not an expert and I do not know much about port forwarding.

Thank you guys for listening me!