Sign into an existing account

Example, I sign in. I read around, then go to other websites. After reading other websites, I go to my bookmarks/favorites, click voat, and I am signed out. WHY AM I SIGNED OUT? When I sign in, in the morning, I click the box that says "remember me", so as to keep signed in, when I return.

I used to notice, IF I had multiple tabs open, and lets say I signed in on the 3rd open tab, when I would go back to voat later I would have to sign in again. I GOT AROUND THAT PROBLEM, by always signing in, with the left most tab. Now that trick doesn't work anymore.

WHY CAN'T MY COMPUTER STAY SIGNED IN???

Desktop, W10, firefox.