From Mi Mouse manual :
Turn on the Bluetooth function on the computer
Hold down the ''connection mode'' button, until indicator light turns on
On your computer find this Bluetooth device (on bluetooth preferences, device name : MiMouse)
Press "connect" for accomplishment of connection of the device
Note that your computer need a Bluetooth chip version ...
Firstly, all iPhones since the iPhone 5s support the Message Access Profile (MAP). For more information see Bluetooth profiles that iOS supports.
As for how you can get this to work, it seems to me you’ve done a great job of trying to troubleshoot this. However, one thing you probably missed (because it isn’t at all obvious!) is the fact you may need to ...
Is there any way to get Bluetooth re-enabled without a USB keyboard/mouse?
If you have accidentally turned off Bluetooth thereby disconnecting Apple Magic Keyboard and Magic Mouse/Magic Trackpad, simply hard reboot your Mac by pressing and holding the power button.
Then restart your Mac, and it will trigger the wizard for connecting keyboard and mouse ...
No - there isn’t another way to pair.
I would keep notes on what steps you see when you click Pair.
Does it ask for a passcode? If so, do you enter 0000 or something else?
Can you unpair other devices and re-pair them. Sometimes if there’s a lot of bluetooth devices or a microwave oven or lots of WiFi right where you are, you could get interference.
I cannot find any Apple documentation stating that the original Magic Mouse is unsupported in newer OS versions.
Your problem is more likely to be just one of Bluetooth connectivity. Apple provides a troubleshooting document that describes the Magic Mouse and Magic Mouse 2 together. Other remedies for problems can be found here.
The Magic Mouse is not one ...
I was having the same issue.
And for me was the apple wireless keyboard and my Logitech MX master mouse.
Basically anything Bluetooth.
As soon as I connected the mouse using the dongle and the keyboard with the charging cable the Apple AirPods 2 start working just fine.
This is very annoying as I can not connect anything to my laptop without getting this ...