LG CX and my Series X will heat the fukk out of a room. Don't know if anyone has a similar experience but it's something to keep in mind.
Out of curiosity, what size room is that setup in? I haven't noticed any huge difference in room temp with my SX/PS5/C1 setup, but it's also in my living room, where it'd be harder to notice.
The upside is that it sounds like at least the fan/cooling setup on the SX is doing its job.