You can open an issue on Github if you want, then I'll have a look at it.
The thing that might happen is that it takes a long time to load the Google Maps, which in turn will prevent the firing of the callback from the update method. I'll check that, I am working on another bugfix for this widget today/tomorrow.
The other possibility is that because Google Maps is not loaded from Google yet, and in the template grid it tries to load it several times. I'll see if I can reproduce this issue/behavior.