WebDav loaded DB results in basic auth popup after period of time

[kaedwen]

Describe the bug
WebDav loaded DB brings up popup to enter basic auth credentials after some period of time (not resolvable)

To Reproduce
Steps to reproduce the behavior:

1. Load a DB via WebDav
2. Everything is working, also syncing the DB
3. Suddenly the browser basic auth popup comes up, in this situation the syncing is broken and re-enter the correct WebDav credentials there does not solve the problem.

The only thing to solve this issue, is throwing away the whole DB and config and reconfigure a WebDav DB load.
I am not sure why this happens, maybe the browser does invalidate the stored credentials? Or maybe the reverse proxy in between? I have no idea and I am a bit lost here, because some family members are not able to reconfigure their WebDav loaded DB and being upset (understandable)

Expected behavior
Re-entered credentials are used