There wasn't a bug as such that changed the lock level of items in line with editor level.

It used to be the case that we had no control of lock levels at all. Various elements had a simple on/off locked flag and the lock level was taken from the level of the last editor. In that situation, if an editor was promoted, every item they locked effectively increased it's lock level, although nothing about the item itself changed.

A couple of years ago, Waze changed this so that, for most items, lock level could be controlled. At that time, the locked flag was replaced by a numerical level and the value was taken from the level of the last editor at that time. Since then, changes in the levels of editors have not affected the lock levels of most items.

One consequence of this in that there are still "legacy locks" left around. Items that appear to be locked unusually highly. We see a lot of L5-locked petrol stations in the UK, for example. That's simply because they were locked a long time ago by a L5 editor - not because someone thought a servo needed to be L5.

Cameras are the exception to this change. Waze never made the change to variable lock levels for cameras, so they are still just on/off for locking and effectively locked at the level of the last editor. We've asked HQ about this a few times, but they don't view it as a priority.