SOLVED Can't pair wireless keyboard over bluetooth

[Calab]

I have an Apple Wireless Keyboard (No usb connection, uses batteries) that I'm trying to connect via bluetooth to my Sequoia Mac.

I open the Bluetooth settings and turn on the keyboard and it appears as one of the devices I can connect to. If I click Connect I get a spinner... and that's all that happens. No PIN prompt, etc. happens.

If I click Connect on the Mac and then press Return on the wireless keyboard a PIN notification pops up on my screen, then disappears immediately, much to fast for me to see the PIN code.

Does anyone know why this is happening and how to fix it?

 

[Rodananne]

Is the keyboard connected to any other devices?

 

[Calab]

I was able to eventually find a support page with some working instructions:

https://discussions.apple.com/thread/255844013?sortBy=rank

A very convoluted way of pairing, but it did work.

 

[Rodananne]

We're up to Bluetooth 6 now so I suppose it's not a big surprise given Bluetooth 2.1 was released in 2007 a bit of fiddling was required.
Well done getting all those Terminal commands right.

 

[Rodananne]

I see they're still for sale although at least it's described as "Vintage" in this ad.