Party frame mana bar always full bug

Im using default Blizzard UI.

Frequently when running M+ as tank/dps, the healer’s mana bar on party frame, will stay full (100% blue bar), even though the healer is no where near full mana, the bug will be persistent throughout the entire run.

I need to target the healer, to see the correct mana in target frame.

It doesn’t happen all the time but frequent enough for me to notice.

This is a good question for the folks in UI and Macro, though the general advice is a full UI reset.