The issue appears to lie in older systems having smaller efi boot partitions that are not able take the new (larger) EFI file that is part of 23.01.
If your system has this smaller EFI partition you will need to reinstall pfSense and restore from a backup.
How to check:
Open a console shell (Serial or SSH) or go to Diagnostics->Command Prompt in the GUI.
Run the command
gpart show
If your output shows partition 1 being '800K' your system will need to be reinstall with the current release. At this time upgrading to ZFS in the process.
[21.02-RELEASE][root@pfSense.home.arpa]/root: gpart show
=> 1 15269887 diskid/DISK-B1D52868 MBR (7.3G)
1 1600 1 efi (800K)
1601 70012 2 fat32 (34M)
71613 15198275 3 freebsd (7.2G)
Larger partitions indicates no need to re-image. This is an example from an 1100 I have installed in the wild:
7cb57d02-72fd-4102-891d-e55794da4857-image.png
Anything that was imaged using 21.02.2 or later should have a larger partition.