Dual User Panel authentication. why?

Hi, I have a problem accessing the user panel.
When I log in, despite having reported successful access, I am obliged to enter my credentials for the second time.
The behavior is always the same, I have to authenticate myself twice.
What could it depend on?
Sorry for my bad english

Hi,

Does this happen all the time or once in a while?
Probably authentication issue.

Are you using the lastest version of cwp?