Sprig "Load more" not loading over https
Sprig will use whatever your site's base URL is set to, to construct the action URL. Ensure in Settings → Sites that the base URL is either set to an absolute path starting with https://, or if an alias or environment variable, that it is defined as an absolute path starting with https://.
Also be sure to either force the www subdomain or force a naked domain. in your example above I see one with and one without www.