Chours Fibre box 300

Arcadyan Vrv9517 router

Netgear AC750 wifi extender 
 
Slingshot fibre provider
 
 
Hope someone can help me out here. My fibre connection is all working okay, not issue connecting to devices. I am trying to add Netgear AC750 wifi extender to the existing network but failed at the very first step which is getting the wifi extender to talk to the router or Chours Fibre box.
 
The Arcadyan router does not have a WPS button. The Chours box does have a WPS button but when click on it it does nothing. No flashing lights and nothing. The extender does light up power and WPS does flashing but just won’t connect to router or fibre box. fibre box, router and extender are all currently sitting next to each other so they are not in different rooms.
 
The WPS is enabled (ticketed) on the 192.168.1.245 page.
 
Anyone have any ideas what I should do? Thanks advance