Amber alerts stop alarm clock from sounding

This morning I noticed that my 3 alarm clocks on my Iphone 7 did not go off at their scheduled time. I am running IOS 11.2.6. I updated the IOS thru Itunes and have rebooted the phone. The Amber Alerts went off at 12:17am and 12:44am. I did not hear either of these alerts. It could of been that I was dead asleep or the fact that my phone's ringer was on silent mode. Do not disturb was not turned on.

I was under the impression that amber alerts took priority over the phone settings and would always sound out just like the alarm clock will sound out when in silent mode.

Anywho... When I woke up this morning and noticed it was already daylight and I was already late for work. I looked at my phone and noticed the amber alert was still showing on the screen, I cleared it and the next amber alert showed up (still no sound), I cleared it also. Then my first alarm started playing (over an hour late), cleared it. My second alarm started playing (41 minutes late), cleared it. Then my 3rd alarm started playing (35 minutes late). Each alarm has different sounds so I know which alarm it is.

Once I got to work and mentioned this to them they asked if my phone had the ringer switch off, and sure enough it was.

The Actual question is why does the Amber Alerts stop your other alarms from sounding at their scheduled time? And if you don't acknowledge them, will they actually stop phone calls from ringing thru?