Whenever a user tries to login into the community, the page refreshes without login in. How could I resolve this problem?

Moved to Tech Support

Just for clarification is this 3x or 4x ?

I have that sometime also, refresh 4 a 5 times with F5  solves it temporarily or clear browser charge data. (als temporarily)

I've have for a week now, no problems more.

(i'am running on 4.1.8.1)