Precision 5570 fans don't start with Ubuntu

We have recently bought two Precision 5570, which we intend to use with Linux for GPU computing. We have installed both Ubuntu 20.04 and 22.04 using the safe mode (it was impossible with the graphic interface). Fans don't start with either version. Is there a documented issue with this model and the control of the fans in Linux? Is this a kernel issue? A BIOS issue? Both?

BTW, we have patched the kernel with dell-smm-hwmon and i8kutils to no avail. Fans don't start, period.

I appreciate any help you can provide.

Julio