Can you confirm it's single vCenter setup and NSX manager is registered with it?
I’m not sure if you saw the images I posted in the initial post but yes it is a single vCenter deployment and the NSX manager is connected to vCenter.
Hi, have you configured VXLAN and the Segment ID Pool?
Could you share the screenshot of the Logical Network Preparation tab and its sub tabs?Bayu Wibowo | vExpert NSX, VCIX6-DCV/NV, Cisco Champion
https://nz.linkedin.com/in/bayupw | twitter @bayupw
Also the vCenter user role on Nsx may prevent creating network services like Security Adninistrator role. What is the role of Vcenter Web client user? This could be seen on NSX Manager >Manage>Users tab