There is something wrong with the theme custom content field (where the yith search and ajax search pro shortcodes are placed).
I checked the page source, and there are some elements and data missing from the HTML output from all of the shortcodes content. (missing icon codes, init data etc..)
However if I place the plugin into the regular page content field, it works properly. There is probably an additional filter applied to the custom content field, which the theme is using (or something else of what I'm not aware of) which could cause this problem, but I highly suggest asking the theme author in this case. Since it's working in the regular page content, I suspect that there is some additional filtering within the theme which alters the search shortcode output HTML. (maybe some kind HTML post processing?)
If you want, you can fill in temporary FTP details, and I can dig into the theme source to see if I find anything related before contacting the theme support.Best,
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