Funnily enough, this isn't happening to me any more. It used to happen to me every few minutes, on both my computer and phone, even if I ticked the box to remember me for this session during login. It frustrated me no end.
And now for some reason, the problem seems to have solved itself ... at least so long as I remember to tick the "remember me this session" box (or whatever it's called).
Such a relief!
_________________
It is easy to go down into Hell;
Night and day, the gates of dark Death stand wide;
But to climb back again, to retrace one's steps to the upper air –
There's the rub, the task.
– Virgil, The Aeneid (Book VI)