I’m not trying to assign blame, but there’s no way any kind of shop should have sent it out the door with the post that far over the line.
Was this a direct-to-consumer sale? “Advertised as being able to fit “ and “assembly video” strikes me that the OP never saw or test-rode the bike until it arrived at his house
Bicycles are also deceptively simple machines, and I’ve seen them adjusted, bodged and modified into all kinds of unusual and confusing conditions, because “they still kinda work.”
Until they don’t.