Try firing up btop in a terminal before you kick off an update in another, that should give you a better indication of what’s happening when the system hangs. Turn on kernel “show kernel threads” so you can spot anything kernel side eating CPU.
Check your kernel journal from the last boot after a freeze, there should be some indication of what went wrong before you rebooted the machine. journalctl -k -b -1 will show you what was going on with the kernel before the machine froze.
Edit: things to watch for in btop: CPU pegged at 100% and no disk activity? Look at the top process, there’s your offender. Super high IO latency but otherwise the system looks normal? Try another drive. Memory completely used and swap endlessly thrashing? Find something to kill to make more memory available.
Turn on “show kernel threads” in btop, they’re off by default, so you can see if something in the kernel is eating CPU time.