The same is now happening in EndeavourOS even though I’ve opened up port 3389 in the firewall.
When I run “ss -ntlp” I see that something called “gnome-remote-de” is listening to port 3389 but when I try that with firewall-cmd, it throws errors saying there’s neither a “gnome-remote-de” service or a “gnome-remote-desktop” service to add an exception for.