@German Casado Fraga (germanobanano) , my test from earlier today was using the same macbook pro but running Windows 10 rather than macos.
I just tested the latest builds 3.1.2 and 3.2 beta and the problem is still present under macos 10.13.6 with the latest NVidia drivers for macos v387.10.10.10.40.140

Just tested on same Macbook Pro with Blender 3.1.2 on Windows 10 and NVidia driver version 425.31. I could not reproduce the issue.

Thanks so much Germano, the issue was that 1) I could not find the key mapping to begin with, 2) after finding them (using the search term "expand"), I noticed that for basic Mask Expand, the falloff hotkeys were set to Keyboard/1 (or 2 3 or 4) instead of Keyboard/Numpad 1 (2,3 or 4). It is now working fine with those keymaps changed.

Additional example: 1) enable dynotopo and 2) draw stroke are both undone with a single Ctrl-Z (just tested in 3.1.2)

Undo behavior is inconsistent/strongly undesired for me. Example:

Some update on troubleshooting:

Thanks Germano, Pratik has already pointed at a driver issue which I have already updated to the latest (see previous posts).

It looks like https://developer.blender.org/D13385 which was commited in https://developer.blender.org/rBae28d90578be516bf81f3532846c29f9985f1085 (part of the 1/7/22 faulty build version rB741ed5fcd2e2) has had some similar freezing desktop issues.

FYI, this is in Cycles CPU mode only.

You're welcome. You are correct, I have tested e6ca0b33e920 which does not show the issue (description already edited)

The problem appears starting with this version:

Despite a bad internet connection at the moment I can help trying to pinpoint which version introduced the issue.

No issue with F12/ final render.

Thanks Germano but the issue exists also without entering Edit Mode by simply enabling Rendered view in Object mode and moving/rotating an object quickly. Let me rephrase the title....

OS Crash: first the screen freezes entirely (no mouse cursor) for about 1mn then the blender viewport updates for a split second before the OS crashes (it seems it only kills the current user session and returns to OS login screen a without a complete reboot)

Thanks Pratik.

Thanks Philipp!

Thanks Jacques!

Thanks Howard and Team!