I tested it with "ungoogled-chromium-bin" and I could not replicate the issue, while navigating through pages, so my feeling was wrong.

But I was able to replicate the session timeout, while typing in the text editor page for one hour. If I try to save the page, it returns the following error:

"You do not have permission to edit this page, for the following reasons:

The action you have requested is limited to users in the group: Users.

You must confirm your email address before editing pages. Please set and validate your email address through your user preferences."

Looking at the top right corner, the website indicates, that I am logged out. It shows:

"User" and not "Keks24"

-Keks