I assumed software but couldn’t work out why that would have had a long hidden issue or suddenly started. The issue was they upgraded the software and it went

I assumed software but couldn’t work out why that would have had a long hidden issue or suddenly started. The issue was they upgraded the software and it went wrong somehow, and Alaska airlines requested the ground stop be issued. ie the FAA didn’t find something wrong, rather AA did (no obvious details - was the upgrade taking longer than expected or was the result going wrong somehow?). Anyway I assume there’s contract rules that make delaying due to a “ground stop” from the FAA better than just a 100% internally driven delay?