24h/12h-clock issue

I have played on both the PC and PS4 and have the same issue with my in-game clock being shown as a 12h-clock and not 24h. This does not apply to the chat-window time-stamps but only the "Server-info UI", where it also shows internet-connection speed and mail-icons. Both my PS4 and PC are set to UTC+01 and to show 24h-clocks. I have an EU SquareEnix-account/client and play with the client set to English. I have heard from other players using the English client who have the clock show in 24h-format and some who, like me, have the 12h-clock, seemingly at random. I have heard from French and German players who have the clock in 24h-format and I have seen lots of videos of the JP-client which also showed the 24h-clock. What criteria do the client use to decide between the 12h- or 24h-clock? As other English-language players seem to have the 24h-clock it would suggest that client-language is irrelevant and it would be great to know how the client decides on 12h-clock vs. 24h-clock.