Pin Map: map background is empty

After using the pin map I was able to specify the longitude and latitude fields, the pins are displaying in the correct positions however the map in the background is grey.
There are a few similar posts, however there was no solutions on those.

Using metabase version: 0.49.12

If anyone has the solution to this, that will be much appreciated

Are you using some custom map?

Yes, I removed the URL and it works now, I didn't realise that the blank url box opened the default version.
Thanks for your help!