Magic Mouse 2 not connecting to iPhone12 pro max

I was hoping/expecting for the Magic Mouse 2 to work with my iPhone 12 Pro Max. However it is not discoverable as a Bluetooth device. I have tried lots of things and spent time watching you tubes on this - which suggest it is possible. I followed all of the advice so far.

Is this is bug and if so do I report this please?

Is you are familiar with this issue and know a workaround please would you let me know? I have tried the standard route of going through accessibility, touch, devices etc but the device does not show up. I have ensure my iOS is up to date - now I am iOS 14.7. I have tried turning bluetooth on/off. I have ensured that the mouse is charged for long enough. I have tried powering the iPhone on/off. By the way, I can confirm that the mouse does work with my wife’s iPADOS which helps to confirm that the mouse is not broken.

thanks