Adding firewall rules via webadmin doesn't get applied to iptables

Maybe I’m just very unlucky or completely not able to maintain stuff like this but I’m again here to ask you guys about something I’ve come across.

If I try to add a firewall rule via the yunohost-webinterface it saves and shows the port as open afterwards.
Have a look here (it’s about port 445 - to access smb):

Here’s the output of iptables -L:

It’s no problem to add the rule manually - but I think it’s quite an annoying bug.
Can I somehow check if there’s an error while adding a rule to iptables?

Eeeh, does it work if you do this from the CLI with yunohost firewall ?

Doesn’t seem to work either.

yunohost firewall allow TCP 445
Warning: Port 445 is already opened for IPv4 connections
Success! The firewall has been reloaded

Ah I didn’t look at your screenshot, but now I think in fact you should look at itables -S, not iptables -L ?

Hahaha - ok, I’m dumb.
It shows, that port 445 is open.

The reason why I thought it’s not “really open” is that nmap shows that the port as closed. Maybe I have to check something else.

Thanks for your help!