iPhone 12, iOS 14.3 - no text message sound notification

Hi Pboarder_2021,

Congratulations on your new iPhone, and welcome to Apple Support Communities! We're glad to help with any issue you're experiencing receiving notifications for your messages.

So that we understand exactly what's going on, let us know more about the behavior you're seeing. Have you noticed a pattern to which notifications you're hearing? For example, does this affect incoming messages from a specific contact? Does it seem to affect alerts from certain kinds of messages, such as only iMessages or only SMS text messages?

Are you able to hear notifications from all other apps? Do you currently use any other devices that receive notifications for your Messages, such as an Apple Watch, iPad, iPod touch, or Mac computer?

If so, you'll want to refer to the information in this guide to determine where you may expect to see your alerts:

Notifications on your Apple Watch

We'd also like to share the following guide with more details about using notifications on your new iPhone:

Use notifications on your iPhone, iPad, and iPod touch

We're here for you if you've got any questions.

Have a great day!

I have this same problem on a iPhone 12 mini running iOS14.3. When my phone is locked, I intermittently will not receive notifications. The notification badge is there on my notifications page, but my phone does not make any sound or vibrate. I receive notification sound/vibration for some texts but many will not. Tried turning on/off, using with Bluetooth off, using with and without Apple Watch. DND is not turned on.

Hi Pboarder_2021,

Thanks for the clarification. Have you noticed if this only occurs when you're actively using your iPhone, or does it occur for messages received when your iPhone is locked and not in use?

If it's only occurring when your iPhone is in use, this may be a function of the Attention Aware features on your device. The following guide has information all about this, and the steps to turn it off, to test if it's the root cause:

About Attention Aware features on your iPhone X or iPad Pro

Let us know how it goes.

Have a great day!