Nope, this is standard in Windows 10 (and 8 and 8.1 for that matter). It’s a “volume overlay” or “volume indicator” rather than a “volume control,” though, because you can’t actually do anything with it.

I believe WizMouse is the application that lets you scroll a different window even if it is out of focus? If so then the reason for the conflict is because this feature is baked into Win10 by default so you’re good to go. :)