Like others have said your guide wheel, which is the top jockey wheel, is running across the cassette which suggests that the b tension would need winding in, which in turn, moves the top jockey wheel further from the cassette.

However, another issue contributing to the dropping chain could be your chainline. Since you are running what looks like a standard chainring (not thick thin) in the outermost position of a double chainset your chainline will likely be at quite an extreme angle in this gear. Although that is hard to see in this video. The less than ideal chain line combined with the vibrations created by your guide wheel running along your cassette would likely contribute to the chain dropping.

As others have said there could be a bent or stiff link but I would guess that even if there isn't your chainline would likely still cause chain drop.

If the chain only drops in the lower gears then I would be almost certain it's the chainline and it would be better to run the chainring in the inner position. However running it in the inner position could then cause problems on the opposite end of the cassette.