There isn't enough information available to understand the problem. Please provide the complete /etc/fstab, blkid, and journalctl -b for a failing boot while booting with parameters:
systemd.log_level=debug rd.debug udev.log-priority=debug
That will sufficiently slow down the boot that if the problem is related to a race condition, the problem may not happen. If that's the case you'll have to do separate boots with one of the above parameters at a time to see which debug method exposes the cause.
-- Chris Murphy