Help with a Gmail login problem ?

Here is a problem which I've been having for a while now: When I attempt to login to my Gmail account, I choose the account, then it goes to the password page. I enter the password, and then it opens up my mail inbox for one second before it returns to the "choose an account page". I have to repeat the choose account / password a second time before it opens my inbox page. I always have to repeat the account > password twice (but not more than twice) before I can access my inbox. I have contacted the Gmail help center, and the "Gmail Community", but have not received any replies. How can I fix that? Thanks - John.