Thank you for the reply, it has been well received.
Unfortunately, I would have to disagree with you regarding it being an iPhone X or iOS 11 issue. As I mentioned before, I have had every single iPhone model since the very first edition. This issue has never happened to me with any other iPhone model, nor has it happened while using any of the previous iOS releases. I did not start experiencing this issue until having the iPhone X, running on iOS 11.
I understand that there could be a lot of factors that could cause this issue. All of the things you have mentioned have been checked, and are not the cause of my problem. I should have listed my issue in more detail, please see below:
I always have 2 alarms set to go off in the morning, just in case the first does not do the job. The alarms will be set for 5:03 am and 5:09 am. Neither of them set to go off exactly on the hour. The alarms will work fine for several days to weeks with no issues. Then, for no reason, the alarms will go off, but only on vibrate, NO SOUND! This is the same alarm that has worked for many days in a row, not a new alarm that was created incorrectly, but the same alarm that has been working just fine.
When this happens, I will then quickly create a new alarm (with sound), to go off the next minute. When the alarm goes off, again, no sound, only vibrate.
I have also noticed that when this happens, my phone will not make any sounds at all, only vibrate. If I receive a phone call, no ringer, only vibrate. Then, when I answer the call, I cannot hear the person on the other end, no sound at all. I have been told that the person on the other end can hear me, but I cannot hear them.
The only way that I have been able to temporarily fix the issue is to delete all of the existing alarms, then do a hard reset. Once the hard reset is complete, will go in and create the new alarms and the sound is back, working like it should. Again, this is only temporary, because eventually the same thing continues to happen. Unfortunately, I never know which morning it will choose to stop working correctly.