Different results compared to OSM Nominatim

Hello,

On Open Street Map I can search for Degreminutes as well: https://nominatim.openstreetmap.org/?q=53°03'04.1"N 8°37'55.4"E

This gives a complete fine result.

When I try the same for mapquest nominatim it gives empty result:
http://open.mapquestapi.com/nominatim/v1/search.php?key=KEY&format=json&...°03'04.1"N 8°37'55.4"E

(also with urlencoded search query: http://open.mapquestapi.com/nominatim/v1/search.php?key=KEY&format=json&... )

Doing a search for cities like "Hamburg" order "Berlin" are working fine.

What can I do to get a result when searching for `53°03'04.1"N 8°37'55.4"E`. I could try to divide the strings and recalculate the LatLng to use reverse search, but since the inputs are varying this wouldn't be a solution in my case.

Best