I just did some testing and I noticed that I am only having this issue with rather large and sophisticated sceneries where I would get 35-40 FPS in the cockpit, but only around 20 FPS in the FBO and exterior view. Moving to a much simpler scenery got me around 50-60 FPS in both the cockpit and exterior view, and 35-40 FPS in the FBO.
However, I realized that after switching liveries in the Airframe Manager, my FPS goes all the way down and caps at 5 FPS, making me have to restart the simulator when doing so.
Thank you!