There is an untrusted PC in the internet behind NAT, but port 22000 is forwarded. I try to telnet to [IP]:22000 of the internet address. It can’t connect. Then I start Syncthing on that PC and try telnet again and it connects. This means the IP and port forwarding, everything is set up correctly. On my local PC I have Syncthing. Both PCs have each other added as remote devices in Syncthing. But there is no connection. I tried the address of remote device locally set as “dynamic” and I also tried specifying address as tcp://[IP]:22000. Nothing helps. Firewalls are off in both PCs.