https://bugs.winehq.org/show_bug.cgi?id=37929
--- Comment #2 from Robert Munteanu robert.munteanu@gmail.com --- (In reply to comment #1)
I suspect this is related to bug 39547: the tooltip steals focus.
At least they have the same workaround: winecfg -> Graphics -> Allow the window manager to control the windows ( disabled ) .
With KDE 5.4 the reported problem no longer manifests itself.