Hi, you are experiencing the dreaded temperature issue which plagues a number of 7900 XTX reference, caused by a manufacturing error of the cooler. Most likely you haven't noticed it with COD because the low settings didn't really load the GPU and thus the temperatures were staying at a decent level.
It is a known issue and a warranty issue nonetheless, AMD clarified this. If you bought it at a decent local store, they should be able to help you out making a warranty claim, the shop should get in touch with Gigabyte to process your request. You can also try contacting Gigabyte yourself and file a claim.
Last but not least you could also try contacting AMD directly, however since the card is distributed by Gigabyte and not by AMD itself, they most likely will redirect you to GB:
https://www.amd.com/en/support/contact-call