Image displaying instead of video

Hello, We are having an intermittent issue at channel.resa.net. At that site, there is a collection of videos streamed by JWPlayer. Usually, the video works fine, but sometimes just the "GoOpenMichigan" image loads without the video. If it helps, we noticed this happening once at 2:24 PM today, and the video was back by 2:28 PM. Often, the video comes back when we refresh the page. We have only noticed this when using our organization's internal WiFi connection. Any insight on this issue would be greatly appreciated.