Please provide the information needed to assist you, please refer to the Looking for tech support article.
https://wp.storelocatorplus.com/forums/topic/looking-for-technical-support-from-the-slp-team-in-the-forum/
Without seeing what add-ons, versions, or site url to look at I cannot venture to guess what is going on with your site. Did you move your site? Are you on a shared server?
Has anyone inadvertently made changes on the page the shortcode is on? If a shortcode shows up it is usually a formatting issue…Did someone copy and past the shortcode?
If you look at documentation site you might find an answer if you do not want to provide your information in the fourms
https://docs.storelocatorplus.com/blog/curly-quotes-in-wordpress-shortcodes/