I managed to fix the scroll (at least back to the intermittent behavior) by pairing the mouse to a Windows 8.1 machine. At first the scroll was still broken, just like on Windows 10, but I installed the Arc app and used the option to "Reset the settings to default".
Clearly, the app on Windows 10 is at fault and publishing bogus settings to the mouse, but at least is not in a firmware level
Now I have my mouse back and can be happy that it just fails every few minutes!