hotshoe bubble on camera test

Video from my Samsung S2 mobile phone
Hotshoe bubble doesn't correspond with cameras digital level.
Flipping the hotshoe bubble around on the hotshoe shows it is not accurate as the bubble should stay in the same position from the center, the bubble shifts from the left side to right side when flipped. Does the same testing on a flat table

[@SilverLarry]

This would be helpful if you mentioned the brand. That way we could avoid this one since there are several brands producing the same product.