Glad it worked for you, but you don’t need to have checked into your resort for the 60-day window to open. I never do online check-in that early (dozens and dozens of trips) and my days have always been open. It was more likely an IT glitch, which does happen fairly often. You were also trying at midnight when reservation time is 6am est. Some experiences are posted at midnight, but some you need to wait until the official time. Regardless, happy you got it figured out.