Depth of Field looks different in viewport and rendered sequence

Hey guys,
Currently I’m working on a short ‘cinematic’ Star Wars animation and I’m using Unreal as a renderer and I stumbled across this issue where my depth of field will look much more noisy (and smaller?) when rendering/exporting a scene from sequencer while it will look much better in the real-time viewport, even when viewing in full-screen/F11 mode. Is it because of the motion blur? It happens in both 4.16 and 4.17.

Sebastian “Shain”