Firewall ports?

I also have the ‘forcibly closed by remote host’ as well. All my syncthing devices are within a local LAN and I have global discovery turned off (all of my devices stay within my home); only the local discovery is on.

However, my router is an apple airport express and it’s known not to be UPnP-friendly. Any settings or ports that I should manually set up? I didn’t forward port 22000 because none of my devices are outside of my local network. Is this correct?

Appreciate the help.