https://bugs.winehq.org/show_bug.cgi?id=55810
--- Comment #3 from Béla Gyebrószki gyebro69@gmail.com --- Created attachment 75406 --> https://bugs.winehq.org/attachment.cgi?id=75406 screenshot (comparison)
I haven't realized this before but only the first attempt to launch the game causes the missing window borders. After exiting the game and starting it again from the same Steam client instance, Wine draws the borders correctly. Then exiting Steam and starting a fresh instance reintroduces the problem the 1st time I launch the game. The upper image shows the game window with Wine-8.18, the image below is with current wine-8.19-317-gdfa0c9d28da.