You're right. I just created a new character and loaded my normal layout then summoned my permanents and they are doing the same thing you describe. So it has to be something individual to the character that gets added as the hireling bars are created at first, and doesn't preserve between TRs because the bars have some unique property. I am obviously oblivious because this is the first I am even noticing this UI behavior. Probably because I don't TR with regularity like everyone else and when I roll for a PD character, I deliberately don't use hires.