Elite passengers in American’s AAdvantage loyalty program have been scratching their heads for the last few months over a strange hiccup in the airline’s upgrade process. Typically, elite passengers on legacy carriers can be upgraded (with space available) anywhere between 24 hours and 10 days in advance — a small perk for being loyal to the airline. On American, however, those upgrades had mysteriously stopped getting processed.

Last week, American rooted out the source of the problem, which was apparently a bug in the upgrade system, and returned the process to normal.

The bug was confirmed by a spokesperson for the airline, saying “we did experience a small technical issue that was impacting upgrades clearing. It’s been fixed and the process for clearing upgrades is working as it should.”

Repairs to the upgrade process couldn’t have come soon enough for the legions of AAdvantage members confused by inconsistency across recent experiences. On Flyertalk, a forum dedicated to airline rumors and discussion, a thread started in March of 2015 had gathered over a thousand posts over the course of 84 pages where AAdvantage members speculated on the source of the problem.

Some believed that the lack of upgrades was an intentional move to hold back seats for last second sales. “AA is holding back the necessary inventory for upgrades to be processed,” postulated one poster on the site. “The general belief is they are hoping to be able to sell those seats for the higher fare instead of allowing those of us that have earned/purchased their script (aka 500-mile upgrades) to get them for a lower price. Marketing 110, tease your customers to stay being customers.”

Others chalked the entire experience up to a conspiracy, pointing out that plenty of upgrades were being processed as normal.

Needless to say, the upgrade snafu was apparently just a bug in the American’s upgrade system, though the airline hasn’t given any further details on the source of the glitch. The system returned to normal last week and elite members of the AAdvantage program started getting upgraded promptly.

Photo Credit: An AAdvantage Citibank credit card. American Airlines fixed its upgrade bug. American Airlines