I think you hit the same bug as @WeaverPixel, in this thread 
I’ll paste the same reply/workaround below…
We’re aware of this bug and it’s actually something we’re working on fixing for the next beta
It’s an issue with the editor not updating (even though the objects are there). To workaround this until the next beta, simply create another page, and swap to it and then back again (you should only need to do this once).
Let me know if that fixes the issue, and stay tuned for the next beta.