Not sure if it is related, but during my last games I was notified that my party-mate was "offline", and when game finished (without any in-game problems) we were not in a party anymore. No restart required for us, just invite again.

@magge that helps quite a lot actually, thank you!

These are the logs I obtained most recently from a disconnect whilst matching on a 3v3 advanced-ice-adapter.log ice-adapter.log client.log

Something in your computer or network is blocking the client's access to api.faforever.com/116.202.155.226:443, check your firewall and antivirus