Xbox Elite Series 2 not pairing to my phone

Hello.

I have tried 3 times in total to get my series 2 elite controller to pair with my phone and I don't know why. I know it has bluetooth but my phone just doesn't pick it up. Why is that?

Some extra tidbits of info:

I have already paired it with my Xbox one (not a One S or X). I paired it with my Xbox before I tried pairing it with my phone

I have yet to try connecting my controller via a wired connection (Lightning to USB-C)

I use an iPhone 11 with the latest iOS (at the time of writing, that would be iOS 13.4.1). I have also tried to pair it before then

Every time I try and pair it, I make sure my console is turned off at the mains so that the controller doesn't pick it up.

I have yet to try pairing with a Windows 10 device

My phone's bluetooth is working perfectly fine. It always picks up my wireless speaker and Powerbeats Pro

Hope this helps!

:)