In the 3.8.x\main\plugin-web\pages\services\resources\search_3.3.xsl
All fields should have an unique Id like in the form-search-element-keywords template :
<div class="label"><label for="search-input-{$uniqueId}"><i18n:text i18n:key="FRONT_MODULE_SEARCH_KEYWORDS"/></label></div>
Please add the unique Id to this templates :
- form-search-element-pages
- form-search-element-creator
- form-search-element-format
- form-search-element-publisher
- form-search-element-rights
- form-search-element-multisite