We eoncountered the same problem today with CheckMK version 2.2.0p12 after upgrading pacemaker to 2.1.6-8 (upgrade from RHEL 8.8 to 8.9)
Obviously the format of the “Last updated” line changed and adds the hostname after the timestamp.
I filed crash report 857ed58c-886c-11ee-974c-e4434bb38c24 for that.