No Alarm sound
Hi, today on my iphone 12 I had a weird issue in the morning when my alarm was showing on screen but it had no sound. Everything else was working like DND, Ring, Volume was full etc. I woke up and decided to set another alarm manually for 5 minutes later and again there was the same issue. There was no sound, just the notification. The issue was fixed after restart but any idea why this issue occurred in the first place? How can i rely on iphone alarm not making me late for work again in the future?
iPhone 12 Pro, iOS 14