[1.1.37] Failed to reach server. Code 520

[Tynian]

Since today I am unable to connect to the factorio auth server, also browsing public games is impossible. See attached screenshots.
Additionaly the game language reverted back to Default. I disabled all mods and tried reverting back to a previous version (as suggested here), without any success.

What happened in detail:
On 06.08.2021, late evening, I was playing with some friends on our server until we suddenly all got kicked. What happened was, that the server did an update to 1.1.37. So we restarted our games to update as well (I am using the steam version) and reconnected. We continued playing for a few hours on 1.1.37 without problems.
The next day I wanted to check up on something and after starting the game the changelog popped up again and the above happened. I can't login with my factorio account ingame and can't connect to any multiplayer games - even if I directly connect with our IP to our server. I will also attach the server log in case it helps.
Since I'm not 100% sure if this is a Bug or a technical problem on my end (haven't seen anyone else on the forums or on steam mentioning this problem), I posted it here for now.

[Tynian]

If someone happens to run into something similiar in the future: Try restarting the steam client. Turns out if there is a new steam version it refuses to load your cloud player profile and for some reason refuses to connect with the factorio authentication server (?).

Anyway, the problem is fixed and the thread can be closed.