https://bugs.winehq.org/show_bug.cgi?id=57547
--- Comment #23 from T E Dixon dixonte+winehq@stc-networks.com --- (In reply to Rémi Bernon from comment #22)
The issue is likely that Wine got access to mouse and keyboard devices, through hidraw or evdev. This is possibly the case if you have added your user to the input group, because you run wine as root, or because of some unrestricted udev rules.
This checks out. I'm not sure why but all the hidraw devices related to my G903 and its charging mat -- and there are a bunch of them -- are set RW for my user. I'll see if I can figure out why and check if this issue goes away. It's not because of udev rules, but perhaps it's Solaar or Piper...
Anyway, thanks. If fixing those permissions fixes this issue I'll let you know.