I have built an app with Google App Maker which has a Suggest Box linked to a table by a Query parameter.
The app works correctly in Preview mode, but when I deploy
I am using Drive Tables as my datasource. The kind people at Google sent me a couple of links which helped me to understand what's going on: previewing and publishing your application and running as user or developer.
The crux of the issue is that when you deploy an app and run it as user (default), it doesn't take any Drive Table data with it. If you want to add Drive Table data to the deployed app, you have to do this:
All courtesy of Google but I didn't find it in the docs, so it might help someone.
Use the browser console to see if there's an error on the connection, make sure the user has access to the datasource and if you're using cloud SQL check the parameters of cloudSQL in the publication