Which setting is blocking the thumbnail before I first press play? Or is it a bug?

[TiagoTiago]

Without the addon, I would see the thumbnail at full resolution instead of a frame of the video before I start playing the video; but with the addon it seems the frame gets loaded on top of the thumbnail (particularly noticeable when "force theater mode" is set, as the sides of the thumbnail are still visible where the black bars will be on the sides when the video aspect ratio doesn't match the space the page is displayed in.

I'm not sure if it was a setting I changed, or if it came after an update, or if it was always like this and I didn't notice when I started using the addon again after a while.