This has been an ongoing issue all season that has yet to be addressed. Videos are taking anywhere from 2 minutes to 10 minutes to load. Support gave me the "you're just going to have to wait for it to load" answer (not their direct response, but it felt more like they just said to go away.)
Was using a samsung galaxy S6, switched over to a Pixel XL over the summer. Heard from somebody else in our club that the issue also exists on the iPhone 7 and the latest iPhone 10.