"Recently" was 3 years ago according to the OP, but you are right that no one knows what was done in the 'service'. From the OP's first post, in recently stopped because of a broken suspension spring. So, there is a legitimate reason other than wear or lack of lubrication for the movement to have stopped working. If the replacement suspension spring is too long, there could be rubbing on the crutch foot, but the pictures and video are too dark to tell. If not that, the pallet bridge was removed, so the escapement may not be working well.