Yup, I can confirm with Shishiro. it can take upwards to 72 hours.I am on Famfrit and was a part of the last Ixion fight. I was the one to mark it down on Ariyala's. and as stated previously it was red for 36 hours. during that period it WILL NOT spawn. afterwards when it went "Open" and numbers turned green I've been diligent constantly hanging around the Lochs. it's been open for 68 hours and 35 minutes. Which I assume means it will force spawn soon.