I was at the New Orleans location for the first time this week. Server called another employee. Employee talked to me for a while, copied down number, and called the manager. Manager said they have been getting hit hard lately with fraud. He said that's why they disabled the ability to check gift card status both online and on the phone. Online just displayed a returning soon message (it's since returned but was down for days). Calling them reached a live person from the chain aware of the recent issues and not anything automated.

He asked me what app I was using. I told him Android Pay. He said they aren't taking any gift card numbers from the phone at all as "they are all fraud". His words that he repeated several times. He said they are only accepting original emails sent from Mellow Mushroom and they were verifying them.

Whether or not you could get lucky and get a server that didn't know better or whatever, unknown...