Nextcloud android app will not upload files i manually add to the sync folders. Is it normal?

Hello.
I have all the non-beta recent versions of server and app at the time of writing.

Here is the situation:

Syncing works fine two-ways on desktop, but, when I do the same on mobile, nothing is being uploaded.

The android app normally connects, and normally downloads on the android device the files that have been modified elsewhere, but it will not upload files that are changed on the device.

Please note: I am not talking about the “auto upload” feature. I am talking about the folders “on device” that the app allegedly keeps in sync.

Even if I manually add a file to one of them (located in android>media>com.nextcloud etc), the app will not show that this file even exists! If I edit a file, not only it will not upload this file to the server, but it will still indicate the timestamp of the old file I have modified!
This even on the “on device” page!

This happens even after deleting cache or deleting the whole account.
No errors visible on the logs on server.

Is this normal behavior?
How to get the app to sync two ways?

Also, are there any logs specific to the android app? Where?

Can anyone please help?