Airport Extreme network extending problems

I currently use an Airport Express (the first gen, wall wart style) in bridge mode to extend the wireless network in my office (which is made up Unifi equipment) to a networked printer using the WAN port on the express. So basically all the Express is doing is serving as a way for the printer to access the network. It works great.

The Express is not really extending the WiFi network because it can only extend a network provided by another Apple AirPort router. The Express has "joined" the network. You can verify this by using AirPort Utility.

The Express does not extend the WiFi when it "joins" a network, but the Ethernet port is enabled so you can connect an Ethernet device or Ethernet switch to the Express. This is a unique feature of the Express which is not found on the other AirPort models.

I recently purchased an Airport Extreme model A1521 because I wanted to add Time Machine backup capability to this setup. I am having trouble with setting it up. In the initial set up step in the airport utility, I choose the option to extend an existing wireless network.

The AirPort Extreme can only wirelessly extend a WiFi network provided by another Apple AirPort router. So it cannot and will not extend the WiFi from a third party network.

In addition, there is no "join" option for the AirPort Extreme, like the AirPort Express. To connect the AirPort Extreme to your network you will need to connect it via a permanent wired Ethernet cable connection. If you need for the AirPort Extreme to provide a WiFi network, configure it to "create a wireless network". If you don't need an additional network, you can turn off the WiFi function on the Extreme. It will still need to connect to the network using the wired Ethernet cable connection.

I'm not really recommending that you use the USB port on the Extreme for a hard drive because the Extreme has an ancient USB 2.0 port that runs at only about half the speed of normal slow USB 2.0 due to processor limitations on the AirPort. Backups will probably work, but you may discover a new meaning for the word S--L--O--W.

Is the extreme defective?

Don't know, but you can find out by connecting it to your network via a permanent wired Ethernet cable connection.

Or is there something about the extreme that is different than my old express that doesn't allow it to bridge to my network like the express was able to?

Yes, we explained that special unique feature of the AirPort Express. Other AirPorts......the AirPort Extreme and AirPort Time Capsule do not have this ability.