Hello @mcgue,
This appears to be a bug in the PSTK. I'm able to do modifications by executing ZAPI directly from PowerShell...for example:
Invoke-NcSystemApi -VserverContext $svmName "<security-ssl-modify><client-authentication-enabled>false</client-authentication-enabled></security-ssl-modify>"
As a workaround, it should be relatively straightforwad to create a custom PowerShell function to wrap creating the ZAPI request for this.
I'll create a new bug for this issue. I'm happy to pay you in NetApp stickers (if you're not already innundated) for finding it : )
Andrew
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