Yeah, that's actually pretty normal behavior for many flight sims, especially if you're using complex scenery add-ons or detailed airports like JFK. The sim often prioritizes loading what’s immediately around the player or aircraft to manage performance.
When you're stationary at the gate, the sim may not render distant or non-essential interior details right away. But once you start moving the camera or "visit" other parts of the airport (like TWA in your case), the sim streams in those assets dynamically.
Some users force the loading by doing exactly what you're doing — moving the drone cam around to “wake up” the sim’s asset loading. If you want more consistent interior rendering from the start, you might want to check your LOD (level of detail) settings or tweak object/scenery loading distances in your sim’s config.