I think you de activated the 4 deg dif with the dip on the indoor unit for low level unit mounting possition.

heating 4 deg dif is standard control for lots of split systems on high wall, cassette & ducted units which will have return air from high level in the room & the manufacturer considers that a good average for warmer air at high level will be about 4 deg dif.

For most systems you can deactivate this function if you use a room mounted remote sensor which is located at body height so the unit will be sensing the same temperature as you unless ofcourse you spend your time hanging from the ceiling