Help Needed with Power BI Filled Maps Visualization

Hi 0Experience ,

As far as I know, the result of filled map is returned  based on bing. 

Power BI integrates with Bing to provide default map coordinates (a process called geo-coding). When you create a map visual in the Power BI service or Power BI Desktop, the Location, Latitude, and Longitude data that's used to create the visualization is sent to Bing.

Halifax is supposed to be a coastal country, and the results of the bing returns are supposed to include in the map the sea area to which the neighborhood belongs.

For reference: 

Create and use filled maps (choropleth maps) in Power BI - Power BI | Microsoft Learn

Best Regards,
Rico Zhou

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