Connection issues - Connection lost for an unknown reason on most multiplayer servers

[The L. U. Z.]

I am experiencing weird connection issues. Last week i noticed that i am unable to connect to most of the multiplayer server.

I have tested all DE and INT servers, DE2 INT1 INT5 and INT9 are the only servers i can successfully connect to. On all other servers i get disconnected "for an unknown reason". When trying to connect as a dispatcher the game loads into the map and after 30 seconds my game gets disconnected. When trying to connect as a train driver, the disconnect happens in the menu.

These issues seem to be directly related to my internet connection, when i use my phone as a mobile hotspot all problems are gone.

My guess is IPv6. While i am connected with my phone, i checked Simrails TCP connections with tcpmon. Connection to the server is established to an IPv6 address. This would make sense because my internet provider completely blocks all ipv6 traffic.

Maybe someone with insights in the server infrastructure can help me with this. (Could also be that i am on the wrong track and this has nothing to do with IPv6) It’s just very weird, that some servers work and some don’t.

SimRail_log_2026-07-06_22-51-08.txt