Mic dictation delay on startup

When I’m using the voice to text feature in text or in an app there is occasionally a delay on start the first time the dictation feature is used after a period of time. When I press the microphone button, there is no beep but it’s waiting for speech, however nothing you say is typed and then after about a second or two it just stops (turns off). Then when you press the mic icon again it instantly beeps and works as it should have the first time. Once this happens repeated use of this feature works immediately as expected, but if you wait an undetermined period of time, it stops working on the first attempt again, almost like the feature goes to sleep and doesn’t wake up instantly. This problem has been on previous iPhone pro max models dating back to the 14 and even on my latest 16 Pro Max (all of my iPhones are on the latest iOS). Perhaps this is a problem with my carrier T-Mobile? Could it be another app or does the dictation feature go to sleep or something? I don’t have a problem with battery life and if there was a way to keep the dictation feature always live so when I press the microphone, it works instantly the first time, every time that would be great. Every time a new iPhone comes out I hope this feature will be fixed, but it never has been in years.