Can't access nextcloud from the android & ios app when connected to the local network

I have a strange problem:
I installed nextcloud (Nextcloud 24.0.9) on a linux server (Debian 11 bullseye).
I have whitelisted all trusted domain names in the conf file.
I configured the internal and external dns names through the dns zone editor.
I can access the nextcloud app outside my internal network using any device and any browser and any app (android, ios).
Internally, I can access the server from any browser. I can also access nextcloud using the Windows app. But when I try to connect to nextcloud using nextcloud app (on android or ios smartphone), it won’t connect. On the same phone that won’t let me sign in through the nextcloud app, if I open any browser and enter the same link that I enter in the nextcloud app it will connect to the site.
My question is:
how does the nextcloud app (android and ios) handle links? and why can’t I connect to the link through the app when I can access it through the browser?

thank you