I moved my PS5 out of my ikea entertainment unit and put it vertically next to my tv, never put a machine vertically before. My speeds went from 30mbps to 150-180mbps and the machine definitely runs cooler. Yesterday when I put my hand on the back left part of the machine it was very toasty inside the entertainment centre. There is an small opening in there, but it's still a mostly enclosed space. The PS5 being so large doesn't leave a lot of empty space around the machine.
This is my new setup:
This is my new setup: