First of all thank you very much for the work you share.
I saw that my problems could come from the plugin WP Better security.
I removed this plugin because the options do not solve the problem.
I wanted to update some points, or the parameters of your plugin and I get this message:
[error_message] => You have exceeded your daily request quota for this API.
[results] => Array
[status] => OVER_QUERY_LIMIT
I said that I had installed Wp Better security before installing Basic Google Maps Placemarks and it worked very well ...
If you had an idea I take!
Thank you for your help.