SNMP v3 problem in MibBrowser

SNMP v3 problem in MibBrowser

I just downloaded and installed the free MibBrowser tool.  I want to query a host that only recognizes authenticated SNMP v3 requests.  I went to MibBorwser "Settings" -> v3 and then add a user to its list.  I entered my SNMP v3 hostIP, userid "xyz" and pass phrases.  I clicked apply and after a short wait, it fails with a "Discovery failed for user xyz".  I traced the SNMP traffic with WireShark.  The actual SNMP packet had the userName "initial" not "xyz".  Is there another place where I have to add my SNMP user to get it to be used during this discovery operation?
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