How to sort knp_paginator

[ikerib]

Hi this is my controller:

public function index(Request $request, PaginatorInterface $paginator): Response
    {
        /** @var EntityManager $em */
        $em = $this->getDoctrine()->getManager();

        $searchQuery = $request->query->get('filter');

        /** @var TransformedPaginatorAdapter $results */
        $results = $this->finder->createPaginatorAdapter($searchQuery);

        $amps    = $paginator->paginate(
            $results,
            $request->query->getInt('page', 1)/*page number*/,
            $request->query->getInt('limit', 10)/*limit per page*/
        );

        return $this->render(
            'amp/index.html.twig',
            [
                'amps' => $amps,
            ]
        );
    }

And this is how my view is created:

<tr>
    <th>{{ knp_pagination_sortable(amps, 'Expediente', 'a.expediente') }}</th>
    <th>{{ knp_pagination_sortable(amps, 'Fecha', 'a.fecha') }}</th>
    <th>{{ knp_pagination_sortable(amps, 'Clasificacion', 'a.clasificacion') }}</th>
    <th>{{ knp_pagination_sortable(amps, 'Signatura', 'a.signatura') }}</th>
    <th>{{ knp_pagination_sortable(amps, 'Observaciones', 'a.observaciones') }}</th>
    <th></th>
</tr>

the problem is that when I click in the table header to get a sorted result I'm getting this error: No mapping found for [a.expediente] in order to sort on [index: app] [reason: all shards failed]

I did a search and tried different things but without results.

Any help or clue?