I suspect that they're trying to push through changes and fixes today which were problematic and/or were rolled back over the weekend. As they do that, we might see it temporarily unavailable again, or with varying levels of information until they get it ironed out.
System conversions are what I do for a living, and working with the 24-hour systems can be the most miserable because there's immediate impact. I used to be actively involved in the Debit/ATM card piece of projects, and occasionally it was days before everything was in line. Usually there were contingencies so that customers were not left stranded and every time a fix was attempted, there were always a couple minutes of down time when they swtiched to the "live" system, and then if it didn't work a couple of minutes until things were rolled back. Usually during one of those brief periods, the wife of a bank officer or board member would be using her debit card for a purchase and be denied, and we'd hear about it.
The one not-as-bad-as-it-could-be thing about the current up and down of the FF profile is that it doesn't seem to be affecting any other functionality. So many people won't be affected, and I would guess that if we on this board were just average joes we probably wouldn't have need or inclination to go into our Frontier profiles on this particular day. I haven't been in my Delta profile in probably two months, and I just flew them the other day.
I have an acquaintence who works in HQ in Indy and she mentioned they had a number of changes and upgrades coming in their internal systems, though she wasn't clear if it was specifically this weekend or a different one. These are probably busy times for the IT people.