404 and white page after instance wasn't used for a while

[metas-dh]

Is this a bug or feature request?

B, afais

What is the current behavior?

When u haven't used an instance for a little while but left it open in a tab, u get a 404, and after clicking the breadcrumb just an empty white page. only refresh gets u back to the window.
afair we used to get back to Login page, if the instance was open for too long, or just clicking the breadcrumb was enough.

Which are the steps to reproduce?

See vid in me03.

What is the expected or desired behavior?