Title says it all. When I use wifi connection syncthing connects no problem, even if I’m not using my home wifi but another wifi connection outside the home. As soon as I switch off wifi and my phone uses it’s data connection syncthing never connects. I do not use a firewall on my rooted phone. I use dnscrypt proxy which works with wifi or data. I use a DDNS app to update my IP address to No-IP, which runs every minute. I can surf using data connection no problem, web pages resolve DNS with no problems.
Any thoughts on why syncthing connects with wifi but data does not?
EDIT: duh, router needed to manually open Port 21027/UDP even though UPnP was setup and functioning .