https://bugs.winehq.org/show_bug.cgi?id=39718
--- Comment #34 from Austin English austinenglish@gmail.com --- (In reply to mactrix from comment #29)
(In reply to Austin English from comment #28)
From that evidence it seems obvious that it was triggered by a change in Steam.
Yes it seems. In this case the issue would also occur on native Steam versions under Windows. So far I don't have confirmation this is the case.
Triggered by, not necessarily caused by. It may end up being valid or invalid, the point is that the Steam changes were the first appearance of the bug.