Face tagging label advances to previous face in Loupe view

This is easily reproducible as I am tagging a recent shoot with 5 people.  LrC 14.2

Library tab, Loupe View - click on Draw Face Region.

Since the automatic face detection misses more than half the clearly visible faces, I am going back through the 250 files and manually drawing and tagging the ones it missed.

An image comes up with one face region, and I have previously corrected that "Person" so it is labeled correctly.  But there are two more people in the photo. 

Steps to reproduce:
1. with the draw face region setting active, draw a box around the face of an un-marked person.

2. check to make sure the new label with "?" is the active input area - about half the time, for some reason, Lightroom leaves the new area and selects the previously-existing person's name label.

That's it - this is the bug. 

It really slows down the workflow, and before I noticed that it was happening quite often, I had already changed the correctly-identified people to others, and had added a bunch of new "?" face regions which were left blank.  If you are looking at the keyboard because of the boring repetition of this action it is very easy to not notice that lightroom has not activated the correct input label.

Maybe related: it seems that whenever this happens, I have had to draw the new region 2 or more times because Lightroom just didn't accept it the first time I drew it around the new face.  It just disappears - no warning, no error.  I thought maybe I was releasing the mouse incorrectly or too small a region, but this happens so frequently even when I'm careful that I suspect it has something to do with triggering the incorrect label selection.