Unsupported nodes sounds like you have one or more X0 appliances in the Grid. Any Infoblox appliance whose model ends in a 0 will not run NIOS 9.0 code. I'd suggest you reach out to your account team at Infoblox or raise a ticket if you don't have their details.

It's also possible it is a certificate issue. NIOS 9.0 is much stricter in enforcing RFC compliance. The detailes are scattered throughout the release notes of 9.0