Brand new magic mouse 2 won't scroll with 2020 MBP / Catalina

Tearing my hair out with this.....hope someone can help. Having spent hours online trying every solution I have no more ideas how to solve this. I have a new 13" 2020 MBP running Catalina. I bought a new Magic Mouse 2 to work with alongside the trackpad. The mouse connected fine, but then created chaos across all the scrolling functions, causing the screen to bounce up and down, even when I'm not touching the mouse. Heres what I've tried...

• Disconnecting and reconnecting the mouse
• Totally removing and reconnecting mouse with cable
• Restarting the computer
• Restarting the bluetooth
• Debugging - removing all other devices from bluetooth and 'resetting' it
• Going in Accessibilty setting and changing TrackPad and Mouse pointer settings to 'Without Inertia'

None of the above have worked - still no consistent and workable scrolling of mouse. I have to turn it off to even be able to use the MBP! I have no more ideas apart from return the mouse to store. But I really need a mouse, I work with Lightroom and Photoshop and can't use 100% trackpad.

Thanks in advance 🙏🤞