We do not set the distances between two points. That is done through Google Maps API. You can check your locations LAT/LONG settings and see if Google API geocoded them correctly. What do you have for add-ons? What is your Plugin Environment? I could assist you with some suggestions if I knew what add-ons you might be using.. If you do have add-ons what versions? you Mixing Versions , is it e updated to the current version of SLP. See the Troubleshooting section
If you updated to WP 4.5.1 ; Use the debugger, your CSS or theme, may be breaking the SLP map, see the article HERE: and the WP articles.
A quick inspect of your site using Chrome developer tools:
FAILURE Failed to parse SourceMap: http://coldlineliving.it/wp-content/plugins/store-locator-le/css/above_all_01.css.map
So something, your theme? or another plug-in MAY USING OUTDATED jquery versions which will cause issues and break the map.
See the tutorial on debugging in Troubleshooting if you need additional help.