Multipath is not creating mpath devices for all devices in RHEL

Issue

• A client noticed that a LVM Logical Volume wasn't complete, missing a single Physical Volume. Running pvscan showed:

 [root@server ~]\# pvscan  
   Couldn't find device with uuid 'xrlmf7-YX4q-jPZB-THLi-DLkO-DqpD-becG4h'.  
   Warning: Volume Group vgTISLNXD1 is not consistent  
   PV /dev/mapper/mpath6    VG vgTISLNXD1   lvm2 [68.08 GB / 68.08 GB free]  
   PV /dev/mapper/mpath7    VG vgTISLNXD1   lvm2 [68.08 GB / 0    free]  
   PV /dev/mapper/mpath8    VG vgTISLNXD1   lvm2 [68.08 GB / 0    free]  
   PV /dev/mapper/mpath11   VG vgTISLNXD1   lvm2 [68.08 GB / 0    free]  
   PV /dev/mapper/mpath10   VG vgTISLNXD1   lvm2 [68.08 GB / 16.31 GB free]  
   PV unknown device        VG vgTISLNXD1   lvm2 [68.08 GB / 68.08 GB free]  
   Total: 6 [408.47 GB] / in use: 6 [408.47 GB] / in no VG: 0 [0   ]

From /etc/lvm/archive backups they could see that the missing PV was at one time /dev/mapper/mpath12, but mpath12 no longer exists.