Onion Skin is not showing correct deformers

Hello, I am using Harmony 21 Premium and onion skinning is not working properly for my deformers. It will not show the deformed contour point on the previous frames, acting as though the previous frames all have the same deformed shape. Is there any way to fix this?

Images to show what I mean. The tail is deformed differently on each frame, but the onion skin is not showing it properly.