Terrible gaming performance

Anybody else getting terrible gaming performance on their OnePlus 12? I mostly play Pokemon Go and set it to 120fps but I find my phone constantly fluctuating anywhere from 15 to 90 fps and very rarely get 120. I've noticed that the GPU usage never goes above about 8% while the CPU is frequently at 100% and temps are usually around 37°c. I never had this issue on my Samsung S23 or S21 and I've seen threads saying the S24 has excellent performance in Pokemon Go so it's not the Snapdragon 8 Gen 3 which I know had an issue with the Unity engine at launch. Is this an optimization issue? Are other people getting good performance and it's just me getting poor performance? I've already tried High Performance Mode both on and off, setting the fps to 60 and using adaptive frame booster, disabled all known app limiters in settings and have uninstalled and reinstalled.

Edit: Thank you to everyone that replied, it sounds like something is possibly wrong with my phone, but I'm also thinking it could be thermal throttling. I'm in Texas and it's been warm (around 80° F) but nowhere near as hot as it's going to get in a few months, and if it's already thermal throttling now it's going to get much worse :(

Edit 2: It looks like the issue stems from my phone not being on the update that fixes thermal throttling (608). When I heard people talking about the latest update fixing thermal throttling what I didn't know was that I got updated to 604 at the same time as others were getting updated to 608. Idk why but it seems that the US, and possibly other regions, are about a month behind on updates.

Thank you to everyone that commented for helping me with troubleshooting. Hopefully I'll get the newest update soon then I'll see if the issues are resolved 🤞