Power reduction when changing virtual gears in zwift Hub

Hi, have had the new zwift hub with the virtual gears and zwift click. When I change the virtual gear the on screen displayed power greatly reduces for a few seconds then jumps back to the actual power output. I have recorded races so I can demonstrate this happening if required but if the onscreen power shown is the actual power then I am losing watts every time I change gears which is not good.
Why is this happening and any fix?