Logout issue within local network - non ha related

I don’t know where to put this. This is no ha issue, but I think I can find the right people to ask here.

Since a few months some accounts don’t stay logged in, but they should.

This happens for me on different devices with different operating systems (macOS, Windows, iOS).

One example is the landing page of octoprint. See here
For Octoprint this happens in all of the above mentioned systems.

I also have this issue with the wdmycloud app on my iOS device.
This app asks you for your login data at the beginning. I worked for years. But currently it ask me for a new auth every few days. It also saves the new login in the webpage. So I currently I have 5 logins from the same device.

Next: ha community (don’t know if this is related or normal). Sometimes I login into the forum, write something and while I’m writing it says “you got logged out, log in again” (or similar).

For me all of that looks like it is the same issue (I could be wrong and those are independent issues), but I absolutly have no idea what could cause this.

I use pihole and duckdns as addons in hassio for a while now. Don’t know if that could be related?

Do you have an idea, @petro ?