Fast Simon app uninstall should also remove our search results page.
There are rare scenarios in which our uninstall script does not work. If this is the case follow these steps to successfully revert to Shopify built-in search results page:
* Install Fast Simon for Shopify app again
* Open the Fast Simon dashboard ==> Search Results page tab
* Switch off the Main Search powered by Fast Simon
Also, in case you added our HTML snippet to your Theme.Liquid file please remove it.
<!-- Fast Simon --><script id="autocomplete-initilizer" src="https://static-autocomplete.fastsimon.com/fast-simon-autocomplete-init.umd.js?..." async> </script><!-- Fast Simon -->