Yep, it's been seen a little bit
Most often happens when copying child styles from one drawing to another, but could have several other possible causes.
(entget (handent "141B")) will tell you what that object is.
(entdel (handent "141B")) will delete it
So I did this and all seemed great. Until I came in this morning and every single feature line I had in that drawing vanished... Whatever entity it is that this deletes it removes all the feature lines from the drawing.