Sync files back into the cloud after editing them locally on mobile


I have a question regarding the use of the mobile app for editing files locally and reuploading them automatically after I saved them.
Here is my context: I am using Nextcloud to access a lot of my research literature all stored as a pdf and like to read them locally on my Android tablet. Hence, I access the files (download them) through the Nextcloud app, usually highlight a bunch of things in the text, close it again and this is then where my confusion starts. On Android (I’m using the Nextcloud mobile app version 3.18.1 right now, just in case that is important), the app is not recognizing the change I made to the file and also not uploading the changes back into the cloud. If I tap on the file again within the nextcloud app, it downloads simply another copy of the cloud file, which is pointless. To get the file back into the cloud I have to manually reupload it and override the old on. This doesn’t make for a smooth workflow, but so far I just thought, ok this feature is just not there.
However, recently I got an iPhone to just play around with and tested the same workflow with the iOS App (vs. and there it does recognize the change and instantly reuploads the changed file. So is the Android app simply lagging behind the iOS app? Or am I missing something in the Android workflow that is required because of the different architecture/platform?

Can anyone help me with this? :stuck_out_tongue: