Same has happened to me. Makes me very leary to use it. Sent from my iPhone using Tapatalk
I only use short bits so I cut the eraser off a new pencil and inserted it in the extender head. The eraser is about 5mm in length by 6.75mm diameter so it will fit nice and tight and will cover the empty space making any short bit sit flat and lock in place without going any further down. Well, at least this trick works for me