You can find information on how to work with multiple icons here: https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS235093
Has anyone else seen this behavior in their Google widgets?
My Google Map don't have that problem when showing multiple icons, so please show us the screenshot of your list of styles ( as shown below), and MarkerFormatting if you have put anything inside.
Another question, was it always shown like this (use Gear icons as markers) ? Or maybe when you have fewer items, every marker appears normally, while as the number of the items increase, not selected markers suddenly became gears?
Please reset your Marker style property for the Google Map.
Secondly, could you please check that if you are using state formatting; if yes; please review it and make sure it does not set the Gear icon.
Do let us know in case of any queries.
I hope it helps.