Uploading huuuge data to your server (?)

I have your device for about 10 days.
Everything works ok.
But…

My phone data manager shows that during this month app Android Auto has uploaded a 5GB data!
Only today - during 20 minutes driving - data upload was 400MB (!)

I mean UPLOAD!

Download is ok.
Maybe 100MB for all this period.
I use a satellite view in Google maps.

My question is:
What do you download from my phone?
Or where is an error?
IMHO it is not possible to such big data consumption “just” for “screen mirroring”

Just as a point of reference, I drive in the car with this device in it about once a week for a few hours so not much BUT from June 21 until today, I’ve used 10Kb of data. That’s a shockingly tiny amount. I think I would start looking at the Google Map app before this device or perhaps you were streaming audio which I don’t do.

Just another point. The Carsifi device is simply an interface between your phone and the Android Auto app. The AA app is the one reporting the data use. Also, are you certain your screenshot is measuring mobile data or could it be WiFi data because the Carsifi device sends the music from the phone to the car over WiFi.