The graphics mode setting is greyed out for me?

Hello, I have a bit of an odd situation. I'm trying to enable the graphics mode setting in my game to try out performance mode, but it's greyed out (excuse the quality of the image; I'm having issues logging into my PS account, so I had to take a picture of my TV screen).

Here's what I've checked/ done to try and fix this issue:

- I have a PS5 version of the game downloaded

- I checked to make sure I had the 120 Hz Output setting enabled -- it's set to automatic -- on my console

- I ensured my TV could handle higher resolution -- it's a 4k TV

- Thanks to another user's help, I know I have a 2.0 HDMI (from my understanding, it should be able to handle 120 Hz)

- I tried doing the obvious restarting my console, reinstalling the game, etc. -- nothing seems to work

- I tested the 120 Hz setting on another game, and it worked perfectly fine

If there's any additional information you need, let me know. I'll answer to the best of my ability.