https://bugs.winehq.org/show_bug.cgi?id=57063
--- Comment #5 from asicosilomu@protonmail.com --- (In reply to mata from comment #3)
Are you sure that those clients actually use the system certificate store on windows? If they don't then they won't do so on wine either. A sign for that might be if they bring their own crypto libraries (something like ssleay.dll or similar in their program directory). They might load their certificates from somewhere else.
I'll report back next time I'm at my computer. Maybe it was just me and Wine isn't at fault here, that would mean something else is making it not work.
I did think initially that the 274 years validity was an issue, but that seemed way too unlikely :)