UE4 slowing to a halt after rendering with Movie Render Queue 4.26

Hi All,

anyone else experienced the above. rendering just one frame using a camera cut in sequencer to MRQ and everytime after producing the frame ue4 slows to a non usable state where everything [click, viewport navigation etc] seems delayed like im treading in quicksand.? ram memory in taskmanager is being half used. Card is 2080ti RTX and utilisation is normal however, even after the render has stopped the usage stays high? When i close the Movie Render Queue the usage stays high until it eventually drops. However usage of UE4 still is not possible due to the continued delay.

I have latest nvidia studio drivers [] and latest build UE 4.26.1 windows 10 up to date also.

anyone got any ideas… still happening…