I have a very strange behavior with OpenWrt and the Nextcloud App on Android (downloaded via FDroid).
When I am connected to my OpenWrt Wifi, it always says "Server unreachable" when launching the app for sync processes.
When I then turn off wifi and use normal mobil data connection, the app works as expected and syncs everything correctly. Also when connected to the Fritzbox of my parents, the apps works without any problem - So I thing the problem is on OpenWrt side.
Adblock was switched of and also the Nextlcoud was whitelisted.
Any Ideas, why it does not work when connected to OpenWrt wifi.
So please explain what ISP the OpenWrt is connected to?
If I understand you so far, you're merely blaming a device that's running OpenWrt (and asking us to guess what's wrong ) for an issue with an app...but you've have failed to actually troubleshoot the connection it has to the Internet.
My guess is that you did not clear all DNS Caches involved in your lookups after disabling Adblock.
Not sure if you understand my setup: My OpenWrt Router is connected to the modem of my ISP and have a working connection to the internet.
I have just mentioned the Fritzbox for my parents cause when connected with the Smartphone to the wifi, the nextcloud app works without any problem.
Only when I am connected to the wifi of my OpenWrt device, the app does not work. When I use the normal browser on the smartphone (also connected via wifi), I can reach the nextcloud.
Cause I have only problems with the nexctloud app connected to the wifi of the OpenWrt router I assume that there must be the error and asking for assistance for troubleshooting in the offical forum.
Thank your for answering. It is hosted on a netcup server (German provider)
Due to my DNSSEC topic I have reset and tested it and it seems, that adblock was the problem and as IIeachii said, the DNS Cache was not cleared after adding the URL to the whitelist. So currently the nextcloud connection via app works perfectly.