Interesting to hear that it is happening in Nazjatar without bodyguards.
I just ran the intro to Mechagon Island scenario (yet again) with my rogue and the Prince with the Rustbolt Rebellion seemed to cause the same kind of problem with my stealth while he was following me around. One of the few times you have a non-pet companion in that zone. I guess the only other time would be when you revive bots.
Anyway, I would like to know if this is a fluke or not. Assuming that it is I doubt it will be fixed so I guess we wait for 8.2.5 or 8.3 or whatever to find out.