I had an interesting series of experiences with an EY award:

Initial reservation tickets in 2 hours without problem.

I make a change to the reservation, which should be a simple exchange. I didn't get a ticket in 48 hours, so call to see what's up. AAgent says everything looks fine and it should be another 24 hours at most.

Another 24 hours passes and no ticket. I call again, and this AAgent discovers something went terribly wrong. Apparently the last agent set up a redeposit/reissue even though it was a change that didn't alter the type of award. There were no miles in my account so it wouldn't reticket. After 55 minutes, agent tells me they've fixed the problem but because it was Thanksgiving Friday, to not expect anything until Monday.

I then got the ticketing e-mail in 2 hours.