Data over consumption with Android plateform

Each Day, my mobile Phone ( galaxy s9+) consume around 300mo of data for no reason. I check the data consumption in the parameters and it seems that the guilty app is the Android plateform. The thing is I have never configured the e-drive, not even the e contact cloud ( I use framagenda).
Do you know what is going on ? Is it a bug or something else ? This over consumption is very problematic.
Thank you

Hi @kuzu is this issue you are facing similar to this bug raised in Gitlab. You can add your comments or a log to the issue.