One of my PocketWizards has been a little flakey recently, it will work fine on a camera as a receiver and on the Studio heads, but will only randomly trigger if mounted as the transmitter on the hot-shoe. A quick dismantling session (there are only two screws on the body) and a peak inside didn’t show any obvious problems. However after reassembly it was clear that there was some movement in the hot-shoe mount, which as it moved was enough to break the contact with the PCB.
Anyway a small blob of glue is sufficient to stop it moving & now seems 100% reliable, I will order a replacement foot (if they are available) and replace the original, not sure that it will make much difference as I don’t know if the issue is with the foot or the body of the transmitter that is worn. We’ll see.