It is pretty common problem with ps4 pro.
U need to clean out the heat pipe perfectly( if too much oily dust inside- use IPA to clean it through). Next u need to do is to clean out the fan and area around.
There is very bad thermal paste used as original and I highly recomend to re-paste the cpu/apu and to use new thermal pads on memory chips. There are only few certain brands recomended to use on ps.
When all the dust is out and there is new thermal paste and thermal pads, you will see a big improvement, it will not be noisy anymore and it wikl work much better/smoother.