SPARQL UPDATE states that optional parameters provided by the user (using-graph-uri, using-named-graph-uri) should be sent as URL-encoded, ampersand-separated query parameters in case of update via URL-encoded POST. Adjust the actual implementation to be compliant with this.
SPARQL UPDATE states that optional parameters provided by the user (using-graph-uri, using-named-graph-uri) should be sent as URL-encoded, ampersand-separated query parameters in case of update via URL-encoded POST. Adjust the actual implementation to be compliant with this.