I knew I had seen this somewhere before. I am having the same exact problem. My maps key works great in a web viewer:
I used the same API key in a Maps component with Google and it worked great in the Thunkable Live app. Awesome! I published it to App Connect and, for some reason, it won’t load the map. I remembered seeing this post, so I went into my Google Cloud Console and created two credentials: an iOS API key and an Android API key. That should do the trick! So, I republished to App Connect and I still have a blank map:
Am I missing something?
Edit: Here’s the Thunkable Live version. Exactly what I want and using the same keys that aren’t working in the published app.