Hi Chris
Can you send me an email address that I can send the dev version to? Use Private Reply.
Follow these steps to manually install:
1) Deactivate S&F in WP Admin Plugins page (do not delete, otherwise you will lose your search form)
2) Via FTP, delete search-filter-pro folder from the wp-content\plugins folder on your server. If you wish to keep the folder, just in case, do NOT rename it, instead move it UP a folder into the wp-content folder.
3) Unzip the file I will have sent to you.
4) Upload the search-filter-pro folder to the wp-content\plugins folder on your server.
5) Go to the Search & Filter Pro Settings in WP Admin and make sure that Load JavaScript & CSS files is ON and Lazyload is OFF. SAVE the settings even IF you make NO changes. This is IMPORTANT to do.
Let me know how you get on.