https://bugs.winehq.org/show_bug.cgi?id=54052
--- Comment #1 from Paul Gofman pgofman@codeweavers.com --- It gives request errors on receiving server response. I think that it is likely some network / server connection issues which give some flakiness here. At least for the first failing place we have a check in the prior WinHttpSendRequest to handle server unavailability gracefully. Error in receiving response is much less likely after that but probably can still happen.
I have MR 1582 (https://gitlab.winehq.org/wine/wine/-/merge_requests/1582) which, as a side effect, can improve this at least for the first failing case: after that MR receiving actual reply should happen in WinHttpSendRequest() so in case of errors there we should fall into the same server unavailability check.
So I think ideally instead of going for checking server intermittent failures in each of those requests in the test I'd wait for that commit to be in first and then look what's left.