Blue Bar Appearing when Scrolling

[picky33]

for some unknown reason when scrolling through videos in full screen I get this blue bar as seen in the image below. it's not transparent like it use to be so it cuts off some of the picture when scrolling through a video. I'm not sure how to change it.

I'm using the latest version of VLC (3.0.2)
Macbook pro
Mac OS high Sierra