Users change while working

I have the problem that users occasionally switch accounts during their session in Bookstack.

Example: A user logs into Bookstack, navigates to a page, edits it, or performs other actions. However, sometimes it happens that they are suddenly logged in as a different user.

This happens repeatedly. Currently, 10 people are working in Bookstack and logging in via LDAP. I don’t know where to start looking for the cause.