The way Zwift relates to your graphics drivers hasn’t changed since the last update, but is there any chance you’ve just recently turned on mouse trails? We’ve noticed with Windows that when mouse trails are enabled, it can make the mouse cursor disappear on-screen while using Zwift. If you do have mouse trails enabled, please disable them.
If you have other apps running while you’re using Zwift, that may be causing a concern if those other apps demand display focus under Windows while you’re riding. If you have apps that are set to always ‘appear on top’ of other running apps, please disable that feature or avoid running apps like that while using Zwift.
Are you sure your spanned monitor setup is correct? Sometimes, when monitor 1 and monitor 2 get flipped, moving the mouse from one monitor to the second won’t work properly and you’ll have to move your mouse to the opposite side of the screen for your cursor to appear on the second monitor. You should be able to change that from your display preferences.