One thing you can try is logging in via ssh, before things lockup, and when they do see if anything untoward shows up in dmesg or any of the other log files.
Does it occur when just running one of the sims from the Linuxcnc menus.
Are you able to use a config that uses Axis, if so does this give the same problems.
Just to confirm your are using one of the images from the downloads page, without an extra packages installed, cos I'm not sure if ctrl-esc gets the task manager. On the RPi5.which is the same apart from the kernel support, it doesn't bring up a task manager.
Before the title was changed, it was mainly to do with the Linuxcnc images, not Linuxcnc on Raspberry Pi OS.
Tommy if you see this can you change the topic heading so it reflects this is support for the Official Linuxcnc Rpi Images, I didn't intend for it to support Linuxcnc on the Raspberry Pi OS. That should be dealt with elsewhere.
I'm pretty sure the original tile reflected that.