Why does my iPhone alarm not ring when phone is on vibrate or Do Not Disturb?

Since the second to last update my alarm clock sound does not ring. I have read everything and it still doesn’t work. Now the one thing I did read is that your phone should not be on vibrate. Well I have either had my phone on vibrate or do not disturb for the last 10 years and it has always worked. I get bank and other family texts in the middle of the night because that’s when they are awake. Why do I need to be awoken by the text just to have my alarm work?

[Re-Titled by Moderator]