Siri not recognizing 24-hour time when setting alarms

How do i get siri to recognize 24hr time (sometimes referred to as military time in the U.S.) when setting an alarm? I have "24-Hour Time" marked under "Settings->General->Date & Time". I do have an older phone (xs) that is limited to iOS 18.

Now, the problem occurs when attempting to use Siri to set an alarm. "Set alarm for zero nine thirty" will set an alarm for the next "9:30" to occur on a 12hr clock. (i.e. if i ask that at 2115, it sets an alarm for 2130. If i ask at 2145, it sets the alarm for 0930.) That occurs with any variation of it, "zero nine three zero", "nine three zero", etc. i can only seem to get it to work if i actually say "nine thirty a.m.", which, awesome... expected, if i was using 12hr time. But why doesn't it work as expected for 24hr time? Or am i just missing something really simple?

I'd prefer not to change how i think of time internally, or convert it manually, when trying to use a quality of life feature.