The RX6750XT can be hot and powercolor cards are not great in the cooling dept. (I had 2 powercolor cards)
Try the undervolting option in adrenalin, it can shave a 5ºC overall.
I had a video showing a more granular control at undervolting but that went away with RX6000 models.
https://www.youtube.com/watch?v=yVFjvizChrw
There's also the MSI Afterburner, a common choice and works with any brand.
If you don't want another app like MSI Afterburner, try the manual undervolting in adrenalin:
Adjust this slider lower than the auto targeted undervolt and stress test, if you get a stable gaming experience, that's it!
Then you can lower or increase depending on stability.
Sometimes you can undervolt and overclock at the same time.
The old faithful RX480 was undervolted and OC'ed.
I liked this control much more than the new one.
Don't forget about a good airflow inside the case.
E boa sorte!
The Englishman