profiles constantly missing

Hi guys,
i use a mikrotik router and the billing software, of late, if a customer logs out and tries to log in sometimes later, it gives them an error message of “profile not found”. at first, i thought the username and password were being entered wrongly, not until i tried it myself. to surprise, the missing profile will be seen on the ticket database if i take it there for confirmation.
i will appreciate all contributions guys.
thanks guys.