I recently received a response from the MileagePlusX team after contacting them about gift card transactions that were being declined. According to their email, the program has implemented several new restrictions on gift card purchases.
The updated limits are applied per merchant and include:
$500 maximum within any 24-hour period
$2,000 maximum within any rolling 30-day period
$5,000 maximum within any rolling 365-day period
Gift card purchases made with miles are capped at $200 per 24-hour period
The email also noted that these changes are part of ongoing updates to the app and thanked users for their patience while the revised limits are being implemented.
For anyone who uses MileagePlusX regularly, these appear to be substantial changes that could affect how the program is used going forward.