Done all the above bud and the issue remains. I've given up with it tbf unless someone has a different suggestion to try.your new cpu, and your mobo is working as intended when you didn't play with bios settings and boosting correctly?
then you played with bios settings and now no longer boosting correctly?
if so then pebcak.
reset your bios and try again. would suggest using a less aggressive curve optimiser first and not touching other voltages.