https://bugs.winehq.org/show_bug.cgi?id=42412
--- Comment #1 from Bruno Jesus 00cpxxx@gmail.com --- It is unlikely that the problem is IP_DONTFRAGMENT. The app may not even be using it. Can you attach a +winsock log when doing the operation? Does this work in Windows? Like Windows->Windows, Windows->Wine, Wine->Windows, Wine->Wine.
Read more about how to get a log at https://wiki.winehq.org/FAQ#get_log