Google Map not displaying on new events
I have also seen this problem, and fixed it. It's nothing to do with CiviCRM at all - it's a recent change made by Google regarding their API and your authorisation to use it.  Existing users seem to be OK, but new users (ie. one of my clients) or maybe even new maps seem to be affected.  You should review your  authorisation to use the Google API for your domain.  It's a slightly confusing situation because it appears that you don't need to enter your API key on Civi anymore, but you do need to be authorised by Google.