Erpnext suddenly change user

I m facing this problem recently when I log in and after a while and suddenly I find myself connected with another user. for example I log in as administrator . after a while the user changes to another . name , profile , even permissions are changed , it’s like a literally logged with the other account . what is happening ?


I am also facing. One of client complaining such behaviour.

An ABC user has no right for Purchase Module, though document shows commnet like ABC created and edited the document.

Witch version of Frappe/ERPNext ?
Where are you hosted (VPS/frappecloud/Amazon, other)?

I faced this issue in both 12 and 13 . we are using our own servers to host our websites . it’s a normal ubuntu server with erpnext installed .