webmail doesn't stay logged in

I am having issues getting webmail to stay logged in. I check the box to stay logged in but every time I restart my browser I have to login again.
I have tried this on 4 different browser. One of them is a clean and new firefox profile. It is the same result for all of them.

Hello. The stay logged in feature only keeps you logged in during a browser session rather than logging you out after a period of inactivity. It doesn’t keep you logged in after restarting your browser. Thank you.