24 hour inconsistencies

Hi,

I have my iPhone 13 and Macbook Air set to 24hr time, but I have noticed that the 24hr time doesn't show everywhere. It shows up in the top corner correctly with 24hr time, however, if I'm in my text messages or mail app it shows the time for old text messages/emails in the standard 12hr time. For example, I sent a text message yesterday at 1504, but it shows it as 3:04 pm, which is super strange. Not sure why it does this, does anyone know how to make it consistent and show it everywhere, or is this just the way the system runs?