https://www.curseforge.com/wow/addons/tidy-plates-threat-plates/issues/613

see title, it just doesnt do anything. doesnt respond at all no matter what i m trying to do. i could change the position of buffs and debuffs without a problem, but in headline view they just dont move.

I just tested with and I could move the aura areas in headline view. One thing to take into account: when you test buffs on friendly units, these are shown (by default) actuall in the debuff area, so you would have to adjust the debuff position. Unless you disable "Switch Area By Reaction".

What you can also try is to enable the configuration mode and try changing the position there. At least you would see if it's the issue as described above