Check your center map…if you have not set anything it will default to the United States which Google has determined to be somewhere in Kansas. The yellow icon is your home marker and the home marker is based on your center map under Settings/Map.
If you want NO home marker and you have the experience add-on you can just check off the setting “Hide home marker”.
If you do not have Experience add on and you do not want any marker indicating the Map center you might want to use the “Blank” home marker icon or you can add your own map marker to your media library.
https://docs.storelocatorplus.com/blog/using-custom-map-markers/
See documentation for more settings.
https://docs.storelocatorplus.com/blog/map-panel-settings/
In the future please provide your Plugin Environment information so that we can better assist you and be more accurate with our answers. See Read before posting guidelines.
https://wp.storelocatorplus.com/forums/topic/looking-for-technical-support-from-the-slp-team-in-the-forum/