Hello Jenny,
Since I assume you are using the WordPress SLP Plug-in , we have no insight into your backend, since you are using the self managed plugin.
What is your plug-in info? (as described in the posting guidelines). If you have the Power add-on try exporting your locations and uploading to Google sheets or another format so that you can readily see what may be missing or different.’ Then you can update the back end. I would do that on a staging site or test site before making any major changes to your list
https://docs.storelocatorplus.com/troubleshooting-large-scale-exports/
P.S.
If you were using the. SLP SaaS platform I could take a look for you to see what is happening.
Every WordPress site is set up differently so I really have no idea what’s happening.
https://storelocatorplus.com