Widget flickers when transitioning

Hi! Great plugin. I noticed that when the widget transitions from static to scrolling with the page, it flickers. Is there a way to eliminate the flickering effect? It seems to only happen while the user is on the transition. Once you scroll a few pixels out of the static position it stops. below is a link to a video that shows this effect happening.

I am using version Version 5.2.0 of the plugin and the latest version of WP.

Thank you for your help in advance!

VIDEO EXAMPLE: https://www.dropbox.com/s/2l5svqbg88iir6c/q2w3-fixed-widget-flickers.mov?dl=0

The page I need help with: [log in to see the link]