I have also seen this issue, it seems to happen with multiple flares but i have only seen it 1 time and didn't test anything. i can try to recreate the issue right now.
I Was unable to reproduce it again but do know it exists, i experienced this 2 days ago. when looking at the flares before black boxes of varying sizes flicker (changing width and height every frame about but still covering) over the area the flare would be on screen.