anordr I'm constantly being signed out on DeoVR today, not sure if it's a site issue or an app issue. One time I literally was signed out as soon as I finished typing the code to sign in.
I'm not saying this has happened to you - but we are only allowed 2 concurrent sign ins and if someone has you login details and they sign in this could make your current login redundant and sign you out.
Maybe look in to changing your password just to be on the safe side.
Also the developers are possibly working on the website and may need to log us out to make an update live.
Also if you go to your account and look at settings - you can see you current logins that are live.
These are just guesses 🙂