I guess there-in lies the issue, in Skyward the red zone extends what looks like 60 miles and does not allow a request to be entered, I assume because it is in the red zone. Your link says at 15 miles you can fly under certain rules. Maybe the issue is with the Skyward app. I just checked Airmap and it appears to be using the 15 mile rule.
Today I received a reply from Skyward saying they are aware of the problem in their software and are working to fix it, that is the red circle incorrectly showing at 60 miles instead of 15 miles as it should be.
IF you want to fly in red zones, try to buy a non-gps drone. I fly in red zones all time, but not with my DJI since it will never take off. Haven't had an issue in 2-3 years. OR you can have the DJI drone upgraded by a third party that will do away with the nanny parameters/restrictions.