Hello everybody,
I've just given my device up in a parcel store to have it repaired by Microsoft.
A last thing I tried before was resetting my Surface Pro 7 with the recovery image from the Surface Support Website.
After finnishing I gave it Wifi and let it install all updates, firmware and drivers via Windows update.
No Microsoft account, no additional software installed, no SD-card or other hardware connected.
Just a naked Windows 10 1909. The issue occoured allthough.
So my only advise is to all od you is to give your device into repair and stop troubleshooting yourselves with energy settings or drivers.
Especialy with energy modes. The device should run fine with the standard energy plan and also the fast boot option should work fine.
Let Microsoft know about our problems by letting them exchange more and more devices!
Greets, Patrick