in one of the previous threads we've discussed this issue.
It seems there is a compatibility issue between 9.5 and NSX-T 2.3 though it says supported in Interop Matrix. I would suggest you to open a ticket with GSS for assistance.
If 9.7 is an option for you then please go for it. It works with NSX-T 2.3. Please refer this thread .Issue in Configuring vCloud 9.5 with NSX-T2.3.