One more point is that there was still some issues in the w10pro64 locale test configurations.
Specifically the UserDefaultLCID, ThreadLocale and Country settings were still wrong for most locales (i.e. still set to en-US). I thought I checked those when I recreated these locales on 2022-04-25 but I found no "Locale check" job around that date.
So I assumed the incorrect settings were caused by the SetWinLocale issue I fixed on 2022-05-02 and I forced the TestBot to recreate all the locale live snapshots using the latest SetWinLocale.
Luckily I think that now it's all good: https://testbot.winehq.org/JobDetails.pl?Key=114459