@leocg again, thats already stated, hell man its in the title, i'm trying really hard not to be rude but it feels like you're not actually reading the post.
in previous comments both myself and @ahsankhan12 stated this happens only on the opera browser (it doesn't happen on opera mobile, or on other web browsers). i think since we're on the opera forums it would be very safe to assume we're logging in to our opera accounts.
and as for what happens, it says it in the title, we get an error saying "2FA session expired".