Created a new User Storage group from Vantage web client. Updated from an active user storage group and saved it from the Vantage web client using the following steps.
'Hosts' selected -> 'User Storage Groups' selected -> edited active 'POOLDEFs' -> selected the newly created User Storage Group -> Saved the User Defined Storage Group.
The newly created User Storage Group is visible under the above active User Defined Storage Group 'POOLDEFs', but it is not displaying in the data for POOLS (Space and Other Attributes) object from Vantage web client (Object Tree -> Storage Groups -> Space and Other Attributes).
Make sure that the VKGPARMS in the PARMLIB has the parameter INCLUSR value set to Y.
Also refer to the KB articles Storage groups PDS member data in incorrect format and Vantage Client: Storage Groups object missing some 'Types' for additional user storage group configuration steps.