I would recommended you to try it with the newest version (V1.20) again. In this version you will also get notified after the first boot in case something did not get setup correctly in your App Build Environment. Maybe this can already give you some hints.
Yes you are right, the App Build Environment is independent from the ctrlX CORE. You don't need to be connected to a ctrlX CORE to work with the App Build Environment.
The Early Adopter Release (like the V1.20 currently, till end of July) you will get from a different folder in the Collaboration Room. See my screenshot: ctrlX WORKS in the Collaboration Room at the path: ctrlX AUTOMATION/ctrlX CORE APPS Releases/V1.20/ctrlX WORKS
If you are not able to see this location please have a look at the FAQ for ctrlX Store and request access to "access level 3".
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