Taprite regulator.

Yesterday I noticed the bonnet on my regulator was feeling tight then it locked up and wouldn't adjust the pressure. After a few attempts the bonnet stripped so I disassembled the regulator to find out the adjustment bolt inside the bonnet needed lubrication. A little squirt of silicon spray. Reassembled and all seems to be working well. Anyone else experience this? And why did this happen? No beer backed up into the regulator.