Performance issue

Bungie Account Name - Redacted9848#9849
Platform - Steam
Description of Issue - My system specs (GTX 1660 Super, Ryzen 7 3700X, 16 GB RAM) fully meet or exceed the recommended requirements for Marathon. On high graphics settings, the game runs at a stable 50-60 FPS, which is acceptable. However, switching to medium graphics settings only provides a minor FPS increase to 60-70 FPS, and it is highly unstable with frequent drops and fluctuations. Given my hardware, I expect stable 75-80 FPS on medium settings