https://bugs.winehq.org/show_bug.cgi?id=42631
--- Comment #10 from Karl Morrison basickarl@gmail.com --- https://issuetracker.unity3d.com/issues/screen-dot-lockcursor-under-linux-br...
If you read the following link above it states, quote:
"I just found something which should've been obvious; if you're still experiencing this problem in October 2015 and it's related to the mouse acting strange when using lockCursor, keep in mind that lockCursor is in fact obsolete and the docs suggest using Cursor.lockState instead."
Perhaps something to look into.