I'll check the BIOS version in the morning, thanks.What BIOS version are you on? The 0707 released 2021/04/28 shows :
https://rog.asus.com/uk/motherboards/rog-strix/rog-strix-z590-e-gaming-wifi-model/helpdesk_bios
Might be worth as others mention, run something like cinebench on both single core and multi core tests, monitor the temps/power etc. and clock speeds in both.