Hi,
I just added my first ZWave devices (Schlage door locks). They pair OK, the device list shows them, but they are not listed in the list for connecting to the endpoint in the Maker API.
I've searched the web and Hubitat docs over and over, and can't find any reference to this. Only pairing and device dropping issues.
Devices have to be explicitly added to the Maker API app before they are available.
Perhaps you forgot to go into the Maker API App and authorize the new device?
Sometimes you have to hit the "update" button to refresh the device list when you click on the device list section - it appears underneath the list on the lower right.