Is it just in the hall? How wide and long is the hall? If you live in a 'regular' home and not a $50M McMansion, it's probably okay.

You could have to removed and laid the other way. Assuming the flooring was just laid, you can just buy more as I seriously doubt the flooring there will be able to be reused.

Hardwood needs to be laid either perpendicular or angled to the floor trusses. It cannot be laid parallel. Your builder continued the same plank pattern into the garage hallway to avoid an unsightly change of wood direction that would have required a threshold piece.

Sometimes a diagonal floor can be a nice design element but if it doesn't work in this case, have it changed to your liking. Generally flooring is laid perpendicular to floor joists/trusses for a reason. It is not so necessary given today's building materials if it is planned for in advance and a T&G subfloor is used. If this was not discussed earlier and directions to the contrary provided, there may be a request for you to pay for the change. You won't know until you ask.

Unfortunately we didn't plan for this……didn't know that we had too so I'm afraid that I am stuck feeling like I am going to slide into the wall every time I walk down that hallway! Thank you for your comment. I will take a photo in the next day or so and post. Maybe someone has an idea on how to make this more visibly appealing.