Depending on which Google Maps API you use on your site, the map that is captured may not be rendered as expected during playback.
Google Maps is typically rendered using WebGL and canvas. While Fullstory does offer limited canvas support, in the case of most Google Maps implementations, the browser doesn't store enough data for Fullstory to capture without significant performance impact to the end user.
While previous versions of the Google Maps API supported workarounds using non-canvas elements, those APIs have been deprecated.