Synchronising taking very long on tablets?

[Zeturios]

Hello there!

We are currently trying to get our head wrapped around the QField Synchronisation Process. But because of the Following Issue we are a bit staggering towards a complete understanding:

We add some data (either QGis or QField) and synchronise thoser via the QFieldSync-Plugin or in the App via "Push Changes". We are then waiting for the Project in the Browser to say it has finished processing the data.

After that is done we press the synchronise button again on the tablet to fetch the latest data but that does not show up - in fact the recent changes made by ourselves were missing on 2 of 3 devices. The third one happened to behave as expected. So did the data on the same day in QGis on the PC.
So we had the pc showing the changes and one tablet but two tablets were not showing any data.

After waiting for a few days and then giving "synchronise" another shot the data appeared.

My Questions:

1. Is there a specific 'best way' to apply changes to the project?
2. Or is there certain amount of time it usually takes for tablets to fetch data?
3. Do we need to give QField new permissions?