Search returns results for empty search term when opened

[metalkramp]

I have enabled search button in navigation only for admins. When I click on button I get redirected to /search and it also returns search results for empty term - "".

I've tried uninstalling and installing dbsearch plugin, restarted NodeBB and behavior is still the same.
This bug occurs only on production, I have same settings on testing forum and it works properly. I'm using version 1.1.2.

I have some custom CSS and following changes made both on testing and production sites:

1. https://github.com/NodeBB/NodeBB/pull/5003/commits/fc68b64fe0565a9252c7f54a82b455f800658c97

2. /nodebb/src/controllers/search.js file:
   http://pastebin.com/J4xPrrGL

3. Custom header:

<script>
$(window).on('action:ajaxify.contentLoaded', function(){
  $('.page-category-480 [component="category/post"]').text('Click here to ask a question')
})

$(window).on('action:composer.loaded', function(event, data){
  // Get the composer elements.
  var comp = $('#cmp-uuid-' + data.post_uuid);
  var catlist = comp.find('.category-list');
  var title = comp.find('input.title');
  if (catlist.length) { // If there's no catlist, then the post is a reply.
    var defaultPlaceholder = title.attr("placeholder");

    // Update the placeholder if category is 480, else set it to the default.
    function updatePlaceholder() {
      if (catlist.val() === '480') {
        title.attr("placeholder", "Ask a question");
      } else {
        title.attr("placeholder", defaultPlaceholder);
      }
    }
    // Update placeholder each time the category changes, and once when loaded.
    catlist.change(updatePlaceholder);
    updatePlaceholder();
  }
});
$(document).ready(function() {
    $(window).on('action:ajaxify.end', function(ev, data) {
        $('.page-search #advanced-search button[type="submit"]').clone(true).appendTo('.panel-body.search-options');
    });
});
</script>

Is there any existing cache for search terms? Perhaps hasn't been cleared properly? Otherwise I'm out if ideas what could be causing this kind of behavior.

[PitaJ]

@metalkramp is your site available to test? It's easier to debug directly.

[pichalite]

Opening search seems to be searching for "" when using the nodebb-plugin-dbsearch plugin. Can't replicate on this community as solr plugin is used here instead.

[metalkramp]

Due to problems with dbsearch plugin mentioned above I switched to solr plugin. Seems to resolve problems that occured with dbsearch + solr gives better search results.