There have been many threads over the years where users changed a metadata field (Artist Sort, for example), then clicked the lock icon, thinking they were engaging the lock. But, since the lock automatically engages when they enter something in the field, they are actually disengaging the lock.
I think it might be a little more intuitive if the ‘unlocked’ icon were a little different.
My suggestion:
I chose to make the lock orange instead of black, to stand out against the dark gray background, and the shank in a more obvious unlocked state.
The ‘locked’ icon can remain as it is, or could be the same orange-on-gray with the shank in the locked position.
. I’ll lend one of mine, at least for a while.