I’m not sure if this will be helpful, but it seems that comparisons should be enlightening. If not, I apologize for the superfluous info… I just went through all of the themes I have installed. Yours is not alone with the problem. The search successfully went to search results with Folio Press, Twenty Fifteen, Twenty Nineteen, Twenty Seventeen, Twenty Sixteen, & Twenty Twenty. It did the same loop/refresh with GP, Customify, Divi, Enfold, Hello Elementor, Image Gallery, Shop Isle, & Storefront.