It seems that Samsungâs default implementation of managing the external storage restricted write access to it.
You can try to go into the developer options of the phone (which you first need to activate) and then enable the usage of external storage by applications.
Once youâve done that, the application still needs to request the permission to write to the SD card
(uses-permission android:name=âandroid.permission.WRITE_EXTERNAL_STORAGEâ) - That way nextcloud should be able to write to your card. Not that that would be needed for uploading your photos from the card to the cloud, but it would of course be needed to keep both in sync.
Iâm not fully sure if nextcloud would be granted to write on the whole SD card though. Might well be that it could only write in its own app directories. Would be interesting to hear from one of the app developers what they actually implemented in terms of requesting write access to the SD card.