Originally Posted by
UnitedSkies
Do you have a stopover at ORD? If so, that's why that's happening. The fare basically has been constructed as a LAXCHI fare + CHICMH fare + CMHLAX fare since the LAX-CMH fare does not allow stopovers.
Dunno the particular instance, but I've also seen where it was just less expensive to book each leg separately, because the through fare priced into a higher bucket was more than a short fare in a high bucket and one or more in lower buckets. For example, in this case, L+H+W end-on-end might be less than H through.
ITA tends to find these things pretty well.