Can't use stylus to interact with the editor?

Someone on our team has been unable to interact with the Unity editor for a while now, and we just finally realised that the problem doesn't happen when he's using a mouse, only when he's using a stylus (his machine is a Wacom MobileStudio Pro 2018).

I've found some threads about this on google, but they're all pre-2015 and suggest that the problem has been long since fixed; we're running 2019.4.13, so it isn't just that our Unity is out of date. Is this still (or once again) a known problem, and are there any workarounds (other than connecting a mouse)?