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Need help diagnosing a weird bug with render targets: white flashes while rendering

Hi, I am working on an open source UAV simulator in Unreal Engine (called AirSim from Microsoft). As part of this simulator, there are multiple drones each having a camera of its own. The views from these cameras are streamed in sub-views in the game, and can also be recorded to disk. The views are treated as USceneCaptureComponent2D inside the code. (I can provide more specific details if needed)

The problem I’m having is that when this streaming happens, I see some kind of flickering going on in the texture being streamed: mostly flashes of white. And weirdly, if I limit the maximum FPS of the game through t.maxFPS: the lower I go, the brighter the images get. If I try to record the images, the flashes become way more prominent. This happens even in really simple maps, and I am not constrained by hardware (i5-6600K, GTX 1070). Even the images that are being saved get recorded with varying brightnesses (or gamma?). Happens on both 4.16 and 4.17.

Video: https://streamable.com/neen8

I am trying to isolate what could be causing this really strange issue. Any suggestions about why it could be happening would be very helpful!