Troubleshoot random server freezes without log entries

We are experiencing a very particular and unique problem on our C# application which is running under .NET framework 4.7.2, in kiosk mode on Windows 10 Operating System that runs on a Lenovo ThinkStation P320 Tiny as Hardware (the same problem was also found on different hardware).

Environment Description:

the scenario includes an always running application, with automatic Day/Night Switch ON/OFF.
When the application is not in video call mode, it plays continuous loop of some videos/films.
The application runs on Windows precisely in kiosk mode at system start-up. The peripherals connected to the Mini-PC(Lenovo) are:

• Primary monitor (Tablet touch)
• Secondary monitor (TV 40")
• Scanner
• USB-Webcam
• USB Microphone
• USB LAN

The only possible user interaction with the system is performed in a controlled environment using a touchable tablet.

Problem Description :

in an apparently random manner we are experiencing a kind of machine freezes:
the primary and secondary monitors are turned on with a fixed image, network interface does not respond to ping command.
The operating system, in this time frame does not track any execution (no crash on the system event log, no dump, no active process running).
Even by connecting the mouse and keyboard to the Mini-PC it is not possible to regain control of the operating system.
There is no precise moment when this type of problem started to manifest itself as we started this project a few months ago.
The same problem was also encountered on different models of hardware different from the Lenovo ThinkStation P320 Tiny hardware used as target.

We have tried unsuccessfully to enable System Event Logs in the Lenovo BIOS Setup Utility but we have not encountered any errors.
We tried to force Dump generation from Windows but the operating system is not able to do this.
We have involved the Lenovo vendor (even if in reality the problem also occurs on different hardware) by performing diagnostic tools that can identify any hardware incompatibilities or intrinsic problems of our company.
Configuration: no problems were found.

In this situation the only possibility is to remove the Mini-PC power supply.
On reboot, by analyzing the application and the system logs, nothing is detected during the time frame in which the Mini-PC was blocked(frozen), no problem is detected in the period exactly before the freeze or after the restart.

Question:

Considering that neither from the application point of view nor from the operating system, it is not possible to get information about system diagnosis and problem analyzing, we would like to understand how to troubleshoot the problem, or enable low-level logs or dumps which can tell us something more about the status of the Mini-PC when it freezes or on the possible reasons which causes it.