Bing map not plotting points correctly on Firefox?

It appears this is a rate limit issue with either the Virtualearth.net API or Bing Maps itself.  There is information on both sites relating to imposed limits, but it's hard to tell which ones would apply to a Power BI report viewed over the web where the integration with Bing Maps is completely out of our hands - this should perhaps be something users are made more aware of?

I solved the problem by using an external tool to get the latitude/longitude for each postcode in my dataset and use those rather than postcodes.

Map plots properly accross all browers, every time, using lat/lng.