I ran into this the other night when I was trying to hide the nametags on player's tokens from them (it was a scenario with doppelgangers and I wanted them to be confused about who was who on the map). No matter how I tried, whether I turned off the "See" checkbox or deleted the text in the Nametag, every time I hit Save on the token it would just automatically reset itself so that the name still showed. It didn't matter that I'm the GM. One of my players suggested it might have something to do with the Aura API that I used to show character health in the form of a colored aura around their tokens, and that that was somehow preventing me from altering the Nametag visibility, but that seemed like a strange reason for it.
Anyway, I wondered if anyone else has run into this and had a solution.