BS_SPLITBUTTON style for standard windows TButton not working

[oxosoft]

hi, i'm all new here, so i hope i'm not creating a topic for something long known. I've been searching the forums for the term BS_SPLITBUTTON with no luck so i'm creating this topic. I'm a Delphi Developer using Delphi XE10.3 and recently i've been playing around with Wine 4.21 staging on Linux Mint 19.2 64bit. I'm quite blown away that my windows applications runs so easily on Linux. I only have one issue i can't seem to figure out. The standard windows TButton control can be configured to use 3 different styles. 1. Pushbutton which is the standard style and works fine in Wine, 2.SplitButton which uses BS_SPLITBUTTON, BS_DEFSPLITBUTTON as style and is available only from Win32MajorVersion >= 6 and 3. Command Link which uses BS_COMMANDLINK, BS_DEFCOMMANDLINK as style and which is also only available from Win32MajorVersion >= 6, both of these last styles do not work in wine and are drawn the same way as the standard button style as soon as i configure wine to be a newer windows version then windows 7. If i leave wine as windows 7 or even vista, all styles work just fine but as soon as i set it to windows 10, they don't work anymore. I tried using gtk3 theming too with no luck either. Except from that i have no issue going on. I attached 2 small images, one showing the splitbutton in windows 10 x64 as it should be and one showing the exact same button in Linux on Wine with wine set to windows 10 (resolutions are not the same as LinuxVM runs scaled whereas windowsVM does not). Is there any known solution to this issue or maybe just a configuration to make other than using windows 7 which is what i'm doing now for the time being ? It's not really an issue as it can easily be worked around, i just would like to understand why this happens as my futur windows developments will keep an eye open on how my windows apps perform on wine.

[DarkShadow44]

Yes, this is missing, see https://bugs.winehq.org/show_bug.cgi?id=20123