Hi,
I think reason why the root aggregates are not listed if you don't explicitly use the -ontapi parameter is because the latest version of PSTK will leverage the built-in ONTAP REST API's instead of ZAPI (IE if you are running >= ONTAP 9.6 it will default to using the REST API unless you use the -ontapi parameter and then it will revert to using ZAPI). The issue is that the REST API does not show the root aggregates. If you test it using the Swagger UI or CURL you'll see the response only outputs the data aggregates (hence why the PSTK is only displaying data aggregates). The ZAPI method will show both root and data aggregates.
curl -X GET "https://<%cluster_ip_address%>/api/storage/aggregates" -H "accept: application/json" -H "authorization: Basic <%base64_encoded_credentials%>"
Hope that explains the reason why. It's nothing you've done wrong, it's by design.
/Matt
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