I booked a multi-segment journey (IAD-MIA, MIA-IAH) on the same day with a 4-hour time lag in MIA with the specific intention of being able to check the bag only to MIA so I could offload it at my condo there before returning to the airport to go to IAH. Yet after I ticketed it, UA is considering it IAD-IAH with a "connection" in MIA. In this scenario, will they still insist on checking it all the way through? Surely they would only check it to MIA if there was a day or two in between the flights. There is no way for me to prove to the IAD agent at check-in that I booked it as a multi-segment. Would it work if I switched it to IAD-MIA followed by FLL-IAH? (I'm assuming UA won't on its own ground-transfer a bag between MIA and FLL, though I suppose they could just put it on a MIA-IAH flight and tell me to pick it up at IAH.)