Trouble remaining logged in

I don’t understand why I keep getting logged out of It’s getting a tad frustrating. If I get up to go to the bathroom I lose all my tabbed pages. I have to re-login on each page. What’s worse is that I am trying to go through flash cards right now and I keep having to re-login even after just taking too long to study the image. I always check the box that says “keep me logged in” but it’s not helping. I hope someone has some suggestions.