Hi Leo,
I used Tom’s php code as below only for using popup-search. Even though I turn this function off, this character is still there.
add_filter( 'generate_navigation_search_output', function() {
printf(
'<form method="get" class="search-form navigation-search" action="%1$s">
<input placeholder="Search ..." type="search" class="search-field" value="%2$s" name="s" title="%3$s" />
<input type="submit" class="search-button" value="">
</form>',
esc_url( home_url( '/' ) ),
esc_attr( get_search_query() ),
esc_attr_x( 'Search', 'label', 'generatepress' )
);
} );