I believe this issue is being caused by your API key. To verify this please try this api key below and let me know if the issue persists.
AIzaSyB0KhffiMteHVLTmx5bdgG4_m2gI5YAFgw
If not then what I would recommend that you do is to regenerate your API key with an unrestricted domain and try that key.
Please disregard my initial response as it seems that i had mixed up my ticket responses 🙁
I must apologize for that.
You issue seems to need some conditional code to make it work.
Would you mind providing me with admin access to the site so that I can check on the page for you ?
The private fields will be enabled for your next response.
The correct solution to this is using our conditional shortcode.
An example can be seen below.
[wpv-conditional if="( '[wpv-post-field name='_regular_price']' ne '' )"]
Display something if the price is not equal to empty
[/wpv-conditional]
[wpv-conditional if="( '[wpv-post-field name='_regular_price']' eq '' )"]
Display something if the price is empty
[/wpv-conditional]
So what you can do is to add your add to cart information in the first conditional and it will only display when you have a price filled in.