@Orion2030 said in DHCPNAK or Offer in VLANS:
I can say that if I connect CLIENT X directly into ports on the Switch, I get IPs for VLAN2 and VLAN3 just fine ( when bi-passing ORBI) but of course I have no clue how ORBI actually handles VLANS.
As I said, that's the issue. A VLAN is nothing more than an extra 4 bytes in an Ethernet frame that a managed switch uses to separate the virtual LANs. If that ORBI doesn't handle VLANs, it can't do anything with them. In fact, since the first two of those 4 bytes are the Ethertype a router wouldn't even recognize those packets as being IP and so won't route them. A router from companies such as Cisco or pfSense can manage VLANs, but consumer level gear generally doesn't, at least not beyond guest WiFi.
I have no idea why VLAN 3 appears to be working, as it shouldn't be. I suspect you may not have what you think you do.