Out of interest is it all games or just one particular game?
You need to run through basic checks ie checking the PS5 is within an acceptable range from the router, what traffic is being used, plotting the property out using something like iperf where you can see how throughput is effected by distance via environment.
You also need to see if it’s connected to 5Ghz or 2.4Ghz.
The PS5 uses an AX1800 chipset and is 2x2 and will have best performance using WiFi 6 based router.
