Why is the 'lvm2-pvscan' service failing in OCS 4.5 and below?

Issue

The service lvm2-pvscan@ is failing to start with messages pointing to duplicate devices. When logging into any of the OCS worker nodes, an error pops up:

[systemd]
Failed Units: 1
 lvm2-pvscan@7:0.service

Inspecting further the status of the service:

systemctl status lvm2-pvscan@7:0.service

● lvm2-pvscan@7:0.service - LVM event activation on device 7:0
   Loaded: loaded (/usr/lib/systemd/system/lvm2-pvscan@.service; static; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2020-08-24 08:12:43 UTC; 23h ago
 Docs: man:pvscan(8)
  Process: 6500 ExecStart=/usr/sbin/lvm pvscan --cache --activate ay 7:0 (code=exited, status=5)
 Main PID: 6500 (code=exited, status=5)
  CPU: 29ms

Aug 24 08:12:43 server1.example.com[1]: Starting LVM event activation on device 7:0...
Aug 24 08:12:43 server1.example.com[6500]:   pvscan[6500] PV /dev/loop0 is duplicate for PVID DziFA5dT0OdONfdk1jHJomuXv4pUxYtm on 7:0 and 8:32.
Aug 24 08:12:43 server1.example.com[1]: lvm2-pvscan@7:0.service: Main process exited, code=exited, status=5/NOTINSTALLED
Aug 24 08:12:43 server1.example.com[1]: lvm2-pvscan@7:0.service: Failed with result 'exit-code'.
Aug 24 08:12:43 server1.example.com[1]: Failed to start LVM event activation on device 7:0.
Aug 24 08:12:43 server1.example.com[1]: lvm2-pvscan@7:0.service: Consumed 29ms CPU time

Why is this so?