I just checked both of my bikes. One is doing just as yours is doing, the other one is perfect. That leads me to believe it is an adjustment and one of the videos should find my problem. I have found these bikes are put together with no fine tuning, the brakes on both bikes were almost dangerous they were so far out of adjustment. Thank you for bring the derailleur adjustment to my attention.It has nothing to do with the rear derailleur adjustment, it's the simple fact that when the chain is in the outermost gear $7, the angle coming from the front chainring is too extreme and that is what causes the rubbing. Derailleur adjustment won't fix this. This is typically a problem you can run into on most bikes with a front and rear derailleur when going from the largest front chainring to smallest rear, or vice versa to make the chain angle extreme. Should not be THIS extreme though, and seems like if the front chainring guard were not there, the chain would happily slip off and often.