In most cases this is related to a so called “Lazy Loading” feature. This can be enabled in plugins like Jetpack, Smush and Essential Grid and should speed up your website performance. However – it conflicts with loading the Location images on the map.
Please disable the “Lazy Loading” feature in the other plugin. Here is a detailed description on how to do this in some of the most popular page speed plugins.
Starting with Version 1.3.6 I will make sure that the location images are always excluded from the Jetpack Lazy Loading. You then can enable Lazy Loading and it will not affect the location images.