I’m afraid that I can’t reproduce this issue on my end. Could you please try to reproduce the issue on one of the WordPress’ stock themes (like Twenty Fifteen) with other plugins deactivated? If it disappears, then you can activate the theme and plugins one by one to see which one causes the issue.
You can also put the CSS and JS code required by Google Map after the Bootstrap’s CSS and JS.
If the issue persists, could you please share the code to show the map?