We have noticed that, using Direct Publisher and Vimeo Pro thumbnails, the images load very slowly on the first screen. By slowly, I mean it takes anywhere from 30 to 60 seconds for the images to appear. Once in a while, I get the '?' icon indicating DP can't load the thumbnail (I assume). Additionally and oddly, some thumbnails load immediately.
This behavior was observed across four different channels (all DP), one that is fully published; as well as from two different internet providers and geographic locations.