I can’t speak for kernel 5.4 but you should be using a newer kernel anyway. 6.1 and 6.6 are good LTS choices. It appears some users are having issues booting with older kernels, so you might want to install a newer kernel, reboot, then start the system update.
If mount | grep cgroup outputs cgroup2, you shouldn’t have issues booting, unless you have a separate issue, of course.