I found a proper fix. The original solution does not allow the scroll to work because the currently available mouse driver on the apple website is an old one, from 2011. Since I have a MacBook I was able to download a more recent version of the driver from Bootcamp Assistant, 2015 version, and when installed on my other windows PC the scroll works perfectly! Now, I can share this driver with anyone that wants it, but I don't know what website to upload it to? It's an .exe file so lots of services block it thinking it's a virus.
I have a new 2021 Dell Precision 5550 laptop (basically a beefed up XPS 15) on which I wanted to use an Apple Magic Mouse. It's no problem adding the mouse as a Bluetooth device under Windows 10, but I discovered that I lost the scrolling functionality when doing so. You can pay a yearly fee for software from some third party vendors to solve this problem, but that seemed absurd. Since I couldn't find any solutions on this message board, I thought I'd post one here. Here are the steps: 1) If you've already added your Magic Mouse as a Bluetooth device in Windows 10, remove it before beginning. 2) Download Apple's Bootcamp Support Software here: [URL] 3) Unzip the file and navigate to the following folder:bootcamp5.1.5769\Bootcamp\Drivers\Apple 4) Double-click on the file AppleWirelessMouseDriver64.exe. This will install the proper driver for the Magic Mouse. 5) Add your Magic Mouse under Windows 10 Bluetooth devices. Done.  
How to install Apple Magic Mouse drivers for Windows 10 (Dell Precision 5550)