What to do is to disable the mouse until you click onto the map and the mouse start working again, if you move the mouse out from the map the mouse will be disabled again.
solution does not work for IE<11, because pointer-events is not supported.
CSS:
<style>
.scrolloff {
pointer-events: none;
}
</style>
Script:
<script>
$(document).ready(function () {
// you want to enable the pointer events only on click;
$('#map_canvas1').addClass('scrolloff'); // set the pointer events to none on doc ready
$('#canvas1').on('click', function () {
$('#map_canvas1').removeClass('scrolloff'); // set the pointer events true on click
});
// you want to disable pointer events when the mouse leave the canvas area;
$("#map_canvas1").mouseleave(function () {
$('#map_canvas1').addClass('scrolloff'); // set the pointer events to none when mouse leaves the map area
});
});
</script>
HTML: (just need to put correct id as defined in css and script)
<section id="canvas1" class="map">
<iframe id="map_canvas1" src="https://www.google.com/maps/embe...." width="1170" height="400" frameborder="0" style="border: 0"></iframe>
</section>