I'm looking at the DemoX course. I have three Android phones, with Android OS v6.0, v7.0, v8.0.
Bug 1) Go to DemoX / Introduction / Welcome to an edX Course! There are two videos in this module: Greetings from Anant! and Anant at TED. They don't look the same in the list. See enclosed image.
[this incomplete; more details forthcoming]