Had a huge reissue problem on Sunday. Originally booked three award tickets together in preferred for LGA-JAX. Split into 2 PNRs for upgrades, and rec'd first class both ways for two. But, IRROPS on the return, first weather and then crew timed out. At first, since plane was at the gate, everyone stayed on the same flight, same seats, just delayed 12 hours more until the morning.
Overnite, DL cancelled the flight, rebooked the two first class seats to first direct flight out in first and the third ticket on the second PNR to an afternoon flight through Atlanta, arriving in the evening. This was our child's first day of sleepaway camp, and the one-day delay already was causing a problem with repacking and getting child away, but separating us parents just crapped on a crappy situation.
On hour on the phone yielded only mysteries, agent and supervisor could see problem but could not find a way to solve it, offering unhelpful itineraries that would arrive later in the evening or even the next day. They give up and I call again two hours later, this agent runs it down with I guess the MR desk, they dissect it back to the splitting, find that something went wrong there, and when IRROPS occurred, the system fell into a loop trying to protect the third ticket, but couldn't, and then defaulted to sending my spouse on a completely different booking.
Finally, it was all undone and redone and my spouse was protected in main on the flight, and could get a seat reservation by paying 3K miles into an exit row. This all took another hour on the phone, but it was done, and by the time we woke up a few hours later, the third seat was in Comfort +. All's well that ends well, but it took dedicated agent time to sort it all out and make it right.