So winehq is ignoring...the bug seems similar to these 'redrawing' issues that some other apps have (also unsolved as yet). Especially since the buttons reappear when the mouse goes over them. I don't understand enough about GDI etc to really get my head around this - I guess we'll just have to live with it !
https://forum.winehq.org/viewtopic.php?t=31396#p136066https://bugs.winehq.org/show_bug.cgi?id=42148
