Wait, are you sure it is GEN?
100 % positive, and you can search on gen owner forum, it's a know issue on some batch of 5711, I don't think it's an issue anymore now, but it was at one point
he also say he sent back to Patek in Swiss and They even cannot fix the problem
He said they refused to fix it, not that he tried to get it fixed, they didn't want to even take a look at it, because they knew exactly what the defect was. It seemed to be a pretty consistent answer at the time of this issue, according to gen owners that suffered from that.
Patek in their mother land should know what to do with the bracelet !
They know what to do, they just don't want to do it, remember, this is not a high end model from Patek, it's in high demand, but that doesn't mean it's treated in the same way other flagship model are.
They considered this was not under guarantee, I'm sure if the customer offered to pay for the fix, they would have done it right away.
It doesn't look like it on the video, but maybe they hide behind the fact that the bracelet was incorrectly sized (one of the reason why, when you buy a gen nowadays, they sized it immediately for you)