Demo uses a static feed whereas live is based off of actual expected volatility. If the pricing doesn’t work for your system(s) then you may not have any trades for that day. Such as with spreads, sometimes the proximity is super high on all of them, making everything except maybe premium collection and low risk with large expected moves difficult to trade. (although now touch brackets have mostly made this a non issue)
The trick here is to learn how to properly read the strike ladders. I was frustrated to no end until I finally learned how to do this. This article explains it Using The Nadex Strike Ladder For Trade Management
I’d suggest posting a screenshot of the strikes for the market you’re looking at tomorrow, tell us your observations/questions/issues with it and we can go from there.