Why doesn't my Text Tone Alert always work?

[iMore Question]

Sometimes it works and sometimes it doesn't. In Settings, I'll go to Sounds, Text Tone, Classic, Alert and when I choose it, it doesn't play all the time. Sometimes I have to tap it 2-3 times before it plays, and other times it never plays. What's up with that? I ordered pizza delivery yesterday for forgot to add my Apt. number online, so the delivery guy texts me for it...but the alert sound never played so I didn't know until I just happened to look at my phone and saw his text. Very frustrating. Same thing happens with calls....the phone doesn't ring all the time (it wasn't on silent) and it goes to a Missed Call. If I don't check it, I don't know someone called me. HELP! And please don't say to do a Factory Reboot like they told me at the Apple Store. I should have to back up all my photos, texts (if that's even possible) and apps just to fix a lousy ringer alert. OK, I'm done venting, LOL.

 

[Just_Me_D]

1. Are you causing the mute switch to be turned on - perhaps when you place the device in your pocket?
2. Is the volume level set to a level that you can hear?
3. Are you accidentally enabling the Do Not Disturb feature?
4. Is something covering the speaker during the times of the incoming alerts?

 

[mikemat56]

1. Don't think I'm accidentally turning on the Mute switch since I have a case on the phone and the switch isn't protruding too much. It takes some pressure to move it to the ON position.
2. Volume is usually set in the mid-level range.
3. Didn't even know about the Do Not Disturb feature, which was set on Manual but I now switched it off anyway. The "Allow Calls From" was set on Favorites, however, so I changed it to Everyone. Under SILENCE heading, it was set for "Only while iPhone is locked", but I don't usually lock my phone. These settings would only affect calls anyway, not texts.
4. Don't think anything is covering the speaker, unless keeping it in your pocket is enough to do that. Don't keep anything else in same pocket as phone.
Thanks for trying to help!