What hardware? And can you narrow down when during updates?
I had this problem on Arch on a 5 year old Lenovo laptop with an Nvidia 1660ti GPU. With judicious use of set -x I narrowed it down to systemd daemon-reload.
I actually changed my ext4 journal mode and added a pacman hook in that calls sync before any systemd hooks ran, after the second time half of the package updates got lost due to the freeze.
Because the problem only happened most times, and usually not soon after a reboot, I can’t prove it, but the problem hasn’t reoccurred since I switched the Nvidia driver to the open flavor.