Haven't found anything either.
Is it possible to try AIQUM 9.7? I use it on two client and had no issue with this integration. 9.8 is really new so not much on the KBs or Bugs...
(although your config seems supported - I checked the IMT)
Also, did you try yo use a different admin user when adding the vCenters?
Take a look at this bug: https://mysupport.netapp.com/site/bugs-online/product/AIQUM/BURT/1381054
Maybe it's the case... it tells to contact technical support.