My crossbow is new and shoots great groups with field points but will shoot just about any broadhead low (5-16 inches at 30 yards). What would be an appropriate course of action?
First, ensure your field points are the same weight as your broadheads. I solved the same problem by switching broadheads. Each kind will shoot a little differently, but some are closer to field points. I find Swackers work for me. Also, if your broadheads hit low, try field points that are actually heavier than your broadheads and see if they hit closer together. If so, just adjust your sights.
It sounds like you may be shooting a lighter field point. Most Xbows over 350fps shouldn’t show that much of a diff between broadhead & field point at close to average ranges. I’ve shot many, with many different heads - I’ve just not noticed a difference at those higher speeds and that close.