I'm flying tomorrow and noticed that one of my travelling companion's KTN disappeared. This is an occasional Frontier IT problem that I've been able to fix by signing into my account, going to the "add KTN" tab and resubmitting it. But this time, when I went to do this, the system wouldn't let me because it couldn't recognize MY frequent flyer number and wouldn't get passed this prompt.

I used Chat and the agent was able to add the KTN and the reservation displayed after I logged into my account on the app. I then checked in without incident.

Bizarre stuff, but just another day interacting with Frontier's IT.