PATCH does not work on turtle

Hi all,
I was unsuccessfully trying to HTTP PATCH a turtle file. If I don't prefix the 'xsd' namespace the patch works.

Original resource:

@prefix : <#>.
@prefix as: <https://www.w3.org/ns/activitystreams#>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix p: <./>.
@prefix notes: <../>.

p:546851bd-1db4-4b8d-bea2-1a33e982c73b
    a as:OrderedCollectionPage;
    as:partOf notes:mynotes;
    as:startIndex "0"^^<xsd:nonNegativeInteger>.

PATCH:

DELETE DATA { <https://diegoalbuquerque.localhost:8443/tests/collections/notes/pages/546851bd-1db4-4b8d-bea2-1a33e982c73b> <https://www.w3.org/ns/activitystreams#startIndex> "0"^^<http://www.w3.org/2001/XMLSchema#nonNegativeInteger>. }

RESULT:

The patch could not be applied. Could not find to delete: <https://diegoalbuquerque.localhost:8443/tests/collections/notes/pages/546851bd-1db4-4b8d-bea2-1a33e982c73b> <https://www.w3.org/ns/activitystreams#startIndex> "0"^^<http://www.w3.org/2001/XMLSchema#nonNegativeInteger> .

This works:

@prefix : <#>.
@prefix as: <https://www.w3.org/ns/activitystreams#>.
@prefix p: <./>.
@prefix notes: <../>.

p:546851bd-1db4-4b8d-bea2-1a33e982c73b
    a as:OrderedCollectionPage;
    as:partOf notes:mynotes;
    as:startIndex "0"^^<http://www.w3.org/2001/XMLSchema#nonNegativeInteger>.

Am I doing something wrong?

Reproduce the supplied PATCH against the original Turtle resource, comparing the prefixed xsd:nonNegativeInteger form with the full datatype IRI. Trace the PATCH handling and Turtle/RDF parsing path; done means the DELETE DATA request succeeds when the resource uses the xsd prefix, with a regression test covering both forms.