Every several minutes(I haven't really measured the time) I keep getting logged out of my accounts. In fact, I don't even notice when it happens.
One minute, I'm fine, next, I try to like/post a comment on YouTube or go to my Gmail account, and it asks me to sign in.
It's not just YouTube, either. I tried on other websites, and it's the same.
What could be the problem? I suspect it has something to do with cookies/cache, but I'm not sure. It started today, just a few hours ago. I think I changed something important in the settings concerning the browser, but I don't really remember what. Sorry for my stupid memory :)
Update:
I noticed that when I open a YouTube video in a new tab, the new tab is logged out, while the original remains logged in. In case it's important.