A WFS service with transactions (WFS-T) can only be altered with a transaction with POST using the WFS 2.0.0 syntax, even when forcing the version in the request to 1.1.0.
Use the WFS-T 2.0.0 syntax to make edits to the WFS.Replace <wfs:Name>OWNERSHIP</wfs:Name> with <wfs:ValueReference>OWNERSHIP</wfs:ValueReference> and the update transaction succeeds.