Fluent breaks silverstripe's fulltext filter (not SearchForm!)

[sirtoobii]

When using the Fulltext filter as documented here, Fluent augments the query with COALESCE which is not compatible with the MATCH, AGAINST syntax.

Steps to reproduce

• Create a locale in the CMS backend
• Add a Fulltext index for Content and Title:

SilverStripe\CMS\Model\SiteTree:
  indexes:
    FullTextSearch:
      type: fulltext
      columns: ['Title', 'Content']

• Setup a dummy controller:

<?php

use SilverStripe\CMS\Model\SiteTree;
use SilverStripe\Control\Controller;

class TestController extends Controller
{
    public function index($request) {
        $query = $this->getRequest()->getVar('q');
        return SiteTree::get()->filter('FullTextSearch:Fulltext', $query)->first()->Title;
    }

}

• Add route:

SilverStripe\Control\Director:
  rules:
    'search/': 'TestController'

• Run a search query: http://localhost:8474/search?q=silverstripe

ENV

Silverstripe: 4.13.1
Fluent: 6.0.0
PHP: 7.4