Upboard freezing - Windows 10 IoT Enterprise 2021 LTSC

JeLa

We have Upboards now in our production series (SKU UP-CHT01-A20-0464-A11 / UP-CHT01-A20-0464-B10).
All upboards are installed with cloned images, so all are exactly the same with Windows 10 IoT Enterprise 2021 LTSC (ESD).
All drivers installed (UP-CHT01_Windows_10_driver 20180223.zip), so no unknown devices and the BIOS is always the same, which was done for us with special company boot logo.
The power button wafer (CN33) is connected to an additional board, which handles power on/off.
The upboard is powered by the HAT 5V(PIN 2), GND (PIN 4) and we check if the board is running, when the 3.3V (PIN1) are available.
The additional board is acting like a batterie buffer with power caps to handle a proper shutdown of windows.
This works well and is aproved.

Some boards don’t shutdown properly and we think they go to a sleep or hibernate and then we can’t boot the system correctly after that unproper shutdown.
We integrated a reset button, which opens the 5V supply from the upboard.
Is there anything we can do to prevent this? The Windows settings should be correct, because most upboards are running correct.

The other and way more critical problem we are facing is, that some upboards are up and running in windows and suddenly the windows freeze unreproducable.
Mostly no mouse movement possible, the clock is stucked and we can just reset the board.

This situation is critical, because we delivered 30 of our systems worldwide already.
What can we do or how can someone help us here?