I was experiencing the same issue and it seems to be related to Gutenberg.
The following seems to have worked for me:
1. Install and activate the Classic Editor plugin
2. Reorder the group position
3. Disable the Classic Editor plugin
Update. The following is needed as well:
– Places API
I experienced the same thing but found a solution.
In the Developer Console, I received the following feedback:
This api project is not authorized to use this api
The solution:
Enable the following APIs:
– Geolocation API
– Geocoding API
– Maps Embed API
– Maps Javascript API
And of course enable billing