something is blocking the connection then
the only thing i can think of sending you is this, said by Paradox:
Connection issues aren't very specific, which means it's impossible to know what's causing the problem.
Lost connection to CoopNet!" or "Cannot connect to CoopNet!"
- Make sure your router isn't blocking the connection to CoopNet.
- Your computer could also be interfering. Try disabling your firewall and antivirus. Also, make sure you don't have a VPN enabled, as those don't work on CoopNet.
- Make sure you have an active internet connection, and that it's able to hold a stable connection. Connection speeds also play a big part in this. If your speeds are very slow, it's likely that a connection won't be established.
- Try changing your DNS and flush your DNS cache. Sometimes that could fix random disconnects.
- Network congestion could also cause random disconnects, so if you have a lot of devices connected to your router, try disconnecting some.
"Failed to connect to player 'Playername'"
Check your NAT type and make sure it isn't very strict. Also make sure you're connected to the main router if you have a double NAT setup, as both of these will cause problems with p2p connections.
Sometimes restarting your device and/or your router will fix the connection issues.