Having the same problem.
I get about 1 or 2 videos and then it goes to a blank screen and then back to the main screen. The bubble that says "no videos available at this time" does not appear. Tried working with Google Ads, App Manager to see if that would help and nothing. First time in a very long time that I've had a problem. WGT has been contacted. With the holiday weekend, don't know if anyone at WGT is working Monday due to the Tuesday holiday. Could be a long wail