Using the touchscreen randomly freezes precision 5540

Hello,

I use a precision 5540 with touchscreen, and I would like to use the latter to check some UI ideas.

But when I use the touchscreen under ubuntu, the computer regularly totally freezes. It happens after having used the touchscreen feature for some random time. When it happens, the image on the screen does not change anymore, and the computer does not react to anything: mouse, keyboard, not anything. It becomes mute on the network, does not log anything anymore. 

I thus have no clue from the logfiles.

Has anybody any idea where that may come from ? Could it be a hardware issue ?

I started with the ubuntu shipped by dell, and have upgraded since to 20.04 and then 20.10, but the issue persisted with all versions. I have not windows installed on the computer.

Thanks in advance for any hint !

Benjamin