Please provide your Plugin Environment, see posting guidelines. It could be a setting in your WP site, t or a number of things.
Are you trying to delete all or are you going through and checking off individual lines and then using bulk actions?
How many locations are you showing at one time being displayed on your WPSLP locations Page? see documentation on how this can be impacted by server capacity. etc.
The last WP update had security patches and anything at all in any other plugins that have javascript errors, or in your theme will stop everything in its tracks. If you have “display locations on your SLP page at a high number and then try to do a bulk delete the WP site can never catch up with drawing the page and it will stop both export and delete. So we really need more information specific to your site.
are using bulk delete or the trash icon? There is an issue with the trash icon that is being patched, but the bulk delete should work….unless you have too many locations on your back end screen display and your server cant handle it