This past long weekend, I flew DCA-FLL on US and then home MIA-DCA on AA, booked through US. Because of the snowstorm, my DCA-FLL cancelled and I had to rebook CLT-FLL through the US call center. Phone agent said I should have no problems with the original return.

24 hours before the flight, I got the check in email from US but couldn't check in through either the AA or US apps. Called US and they said the ticket was still fine but I'd have to check in with an AA agent at MIA.

When I got to MIA yesterday, it took the AA agent about 30 minutes to reach someone at US to get my new eticket number, as her system was showing me as EXC. It worked out fine because I was traveling with a friend who was on an earlier flight and so got to the airport much earlier than I usually do, but I did feel bad holding up the line behind me while the one priority access agent tried to figure out how to issue my boarding pass.

Is there any way to avoid this in the future, such as asking US for the new e-ticket number (I didn't see one on any of my new documents)? I have a couple mixed itineraries coming up and getting to the airport two hours before for a domestic flight is not really something I plan to do.

Thanks!