I have setup automatic blinds and they are connected to Google Home via an app called “Connector” the blinds are from Wystan. I CAN control them with my voice and the Wystan app. However as Google Home has terrible routines I wanted to use Smartthings. I can add the Connector app to smart things but the blinds don’t show up in the app.
Did you check the Not in Use or in All Devices under the Devices tab from the lower menu > home icon in the upper left of the screen? Sometimes, devices are placed in Not in Use even if you selected a Room during the install.