Cannot get iptables persistent

I’ve added three rules to make KDEConnect and Chromecast support working, but it doesn’t stay persistent even if the rules are saved in /etc/iptables/rules.v4.

The normal “sudo iptables-save > /etc/iptables/rules.v4” doesn’t work - I have to do sudo su before, but this doesn’t seem to work.

Any ideas? Thanks in advance :slight_smile:

EDIT: iptables-persistent is installed as well.