Parameters <ItModesToCover> ignored?

[GerdC]

I use this example trip request:

<?xml version="1.0" encoding="UTF-8"?>
<Trias xmlns="http://www.vdv.de/trias" xmlns:siri="http://www.siri.org.uk/siri" version="1.2">
    <ServiceRequest>
        <siri:RequestTimestamp>2024-03-08T18:28:23Z</siri:RequestTimestamp>
        <siri:RequestorRef>xxx</siri:RequestorRef>
        <RequestPayload>
            <TripRequest>
                <Origin>
                    <LocationRef>
                        <GeoPosition>
                            <Longitude>9.184256324324323</Longitude>
                            <Latitude>48.77452167567568</Latitude>
                        </GeoPosition>
                    </LocationRef>
                    <DepArrTime>2024-03-08T18:28:23Z</DepArrTime>
                </Origin>
                <Destination>
                    <LocationRef>
                        <GeoPosition>
                            <Longitude>9.19643</Longitude>
                            <Latitude>48.782425</Latitude>
                        </GeoPosition>
                    </LocationRef>
                </Destination>
                <Params>
                    <BikeTransport>false</BikeTransport>
                    <NumberOfResultsBefore>1</NumberOfResultsBefore>
                    <NumberOfResultsAfter>3</NumberOfResultsAfter>
                    <AlgorithmType>fastest</AlgorithmType>
                    <ItModesToCover>walk</ItModesToCover>
                    <ItModesToCover>cycle</ItModesToCover>
                    <IncludeTrackSections>true</IncludeTrackSections>
                    <IncludeLegProjection>true</IncludeLegProjection>
                    <IncludeTurnDescription>false</IncludeTurnDescription>
                    <IncludeAccessibility>true</IncludeAccessibility>
                    <IncludeEstimatedTimes>true</IncludeEstimatedTimes>
                    <IncludeSituationInfo>true</IncludeSituationInfo>
                    <IncludeIntermediateStops>true</IncludeIntermediateStops>
                    <IncludeFares>false</IncludeFares>
                </Params>
            </TripRequest>
        </RequestPayload>
    </ServiceRequest>
</Trias>

My problem is with those two parameters:

                    <ItModesToCover>walk</ItModesToCover>
                    <ItModesToCover>cycle</ItModesToCover>

According to this documentation
https://www.mobidata-bw.de/dataset/3e6eb9a8-f119-4fdf-901a-7aab53a662dc/resource/adf083ca-56ce-44db-94dc-0bedf198d7b1/download/mentz-datenmodellbeschreibung_-trias-1.2-dokumentation-trias-1.2-kundendokumentation.pdf

The parameters are supported and should result in a direct walking trip and a direct cycle trip.
But whatever I do, the parameters are ignored.

Am I doing something wrong?