Account logs out automatically (Xbox One X)?

My account simply logs out while playing. But that doesn't happen when I play offline. I think it's because of the bad internet but I'm not sure and why should my account be logged off and not just Xbox live.

I'm in despair, please help.

Happened to me on my One S several times, once while I was in the ace combat 7 campaign - with a 4 hour challenge, everything messed up. Kick your Xbox account from the one, and download it again (so log in, if you log in for the first time, download your xbox account) or reset your console (but keep the database) but make a backup with some play like Minecraft, because the worlds are inevitably lost, the experience had to be done by myself: /

Was with me too, I reset the xbox and then it was gone