Alarm ringing on screen without sound or vibration

My iPhone 15 Pro has been doing this to me a lot recently. First of all, if anyone tries to give me advice on how to set alarm properly, I've done it already. Whenever it does not ring, I wake up to it showing me the screen of the alarm ringing but without sound of vibration, and a notification from boss!

Recently this happened because I put my phone on silent, but it SHOULD NOT be affecting the alarm.

If anyone from Apple would be so kind to finally address this issue instead of telling me how to set an alarm "properly"?

[Edited by Moderator]