https://bugs.winehq.org/show_bug.cgi?id=39352
--- Comment #1 from Michael Müller michael@fds-team.de --- This also affects the launcher of "Seven Kingdoms II: The Fryhtan Wars" in the exact same way. You have to force a redraw for example by moving the mouse over the buttons.
A demo is available for download at https://archive.org/details/SevenKingdomsIITheFryhtanWars_1020