WFS 2.0 GetFeature fails on filter with TimePeriod

Description

This filter (put in a GET request) fails to parse due to a class cast exception:

<fes:Filter xmlns:ns44="http://cite.opengeospatial.org/gmlsf"
	xmlns:wfs="http://www.opengis.net/wfs/2.0" xmlns:fes="http://www.opengis.net/fes/2.0">
	<fes:During>
		<fes:ValueReference xmlns:tns="http://cite.opengeospatial.org/gmlsf">tns:dateTimeProperty
		</fes:ValueReference>
		<gml:TimePeriod xmlns:gml="http://www.opengis.net/gml/3.2"
			frame="http://www.iso.org/iso/iso8601" gml:id="TP01">
			<gml:beginPosition>2006-06-28T04:08:00Z</gml:beginPosition>
			<gml:endPosition>2009-06-28T06:08:00Z</gml:endPosition>
		</gml:TimePeriod>
	</fes:During>
</fes:Filter>