XPATH assertion fails with SoapUI NG

Hi together,

I want to migrate our projects from SoapUI Pro 5.1.2 to SoapUI NG. Within SoapUI NG the following XPATH assertion fails, which passes within 5.1.2.

As result of a REST request I check the returned codes, that have always different order.

<codeCategories><codeCategory>A</codeCategory><codeCategory>B</codeCategory><codeCategory>C</codeCategory></codeCategories>

XPATH Assertion example

Expression

//codeCategories[1]//codeCategory

Expected result

B

Returned error

XPathContains comparison failed for path [//codeCategories[1]//codeCategory], expecting [B], actual was [[A,B,C]]

Why does the assertion under SoapUI NG fail with the returned error?

Thanks to all