[Resike]

You can't anchor stuff to the MultiBarRightButton7 not to the whole MultiBarRight, since the multibar is protected so every time the Boss frames appears that pushes the MultiBarActionBars to the left in combat (if there is enough Boss frames to push it (but the SetPoint update runs even with 1 visible Boss frame, or even when the game just decides to run a full frame update)), which cause taint all across every anchored and child objects. The root of the issue is that the TargetFrame gets hidden and shown in combat, since you kinda want to target and untarget units while in combat too.

This is the same fiasco that happens with the MiniMap, since Arena frames are anchored to the MiniMap, you can't so anything protected with the MiniMap in combat, as long as the protected Arena frames are anchored to it.