I trying to update my status to Offline (Skype for Business) , by POSTing
{"availability":"Offline"}
to me/presence url.
The response is: 400 Bad request
<code>BadRequest</code>
    <subcode>ParameterValidationFailure</subcode>
    <message>Please check what you entered and try again.</message>
    <debugInfo />
    <parameters>
        <property name="availability">Invalid</property>
    </parameters>
Same happens with 'Away' status, but statuses like 'Online', 'Busy' work fine.