Exclusion/inclusion of pages not working on WordPress.com site

I am trying to exclude a set of 10 pages from general site search that is accessed from the menu search icon, and also to include a search field at the top of the Table of Contents page for those 10 pages (using the shortcode block in the block editor) that will ONLY search those same 10 pages. Ivory Search seemed perfect for this, with clear, easy to understand settings, but neither the exclusions or inclusions are working – both forms search the entire site. I initially set up both forms by editing the custom search form template, and also tried it using the Ajax form when that didn’t work (though weirdly, it initially seemed to work, then stopped). And yes, I cleared the cache. Is there any known issue that would keep this plugin from working on a WordPress.com site?