Weird Performance Issues on High End PC

Hey. I wanted to reveal my view on the performance of Marathon with this feedback. 

I play the game on 2K Res and have everything on the highest setting with DLSS on DLAA. I have an AVG of FPS between 130-180 most of the time in Fullscreen. Today i did a test with Windowed mode and hit numbers like 170 to sometimes 200 FPS. I was outside at Perimeter to check the FPS in general. Depends on which map I am on (for this test it was PERIMETER), let alone in a building or outside. My GPU is usually utilised between 60-70% and the CPU is between 50-70%. Since you collect information regarding performance issues of various hardware, you have an example of Top Notch Hardware. The game may be completely CPU bottlenecked but for the fastest CPU currently on the market and this FPS that I achieve I am already quite disappointed. I hope and pray you can fix something there.

CPU: RYZEN 9800 X3D

GPU: RTX 5090

RAM: 32 GB 6000 CL28

WIN 11 and the newest NVIDIA Driver 595.59