Nothing appears wrong, and although some young stems on Arrowood can indeed be fairly straight, it's not uncommon for others to arch. If the downward bend in these branches is bothersome, you can cut them back to just above a node (where leaves attach) near to where the angle of the arch is closer to upright. New growth will eventually arise from dormant leaf buds at that node, and will probably head more upwards or outwards instead of down. It might be the case that when the plant was still in its pot before purchase, it fell over around the time new growth was expanding, and a few branches oriented themselves to the new direction the light was coming from, so when put back upright, that new wood was then angled off to one side. It's a guess and might not be the cause for arching (or explain why it kept going in that direction), but the bend itself does not indicate a problem in this case.

Miri