Receiving a notification decreases volume

Hey there jaypatel1995,

Thanks for reaching out to Apple Support Communities. I’ll be happy to help with this concern about your notification volume lowering at certain times. 

It sounds like this could be related to the Attention Aware features of your iPhone. With this on ‘If you're looking at your device, it will lower the volume sound of your alerts.

If you don’t want to use these features, go to Settings > Face ID & Passcode and turn off Attention Aware Features.’ You can read more about this here:

About Attention Aware features on your iPhone X or iPad Pro

Regards.

This does not explain my issue which is IDENTICAL to the other poster replying to your post.

I have an iPhone 8 Plus running iOS 13.4.1 and this issue is new since the last update or possibly the update before.

My issues is that the volume (in any app using sound) decreases when I receive any notification but the volume does NOT return to the previous volume level after the notification is timed out & screen goes black. Even when I physically dismiss the notifications or click thru to the app from the notification there is no change. I have to use the volume on the iPhone or headphone buttons (multiple make/made used).

I don’t believe the IPhone 8 has face recognition and therefore doesn’t have the Attention Aware feature so your explanation doesn’t explain my issue.

Sorry this was so long but I’m very frustrated and I didn’t want to leave anything out.

No, this is not true! However this bug may be related to the Attention Aware feature. I also have this bug since updating my iPhone 11 Pro Max to 13.4 and it is driving me nuts. Everytime I watch a video or the phone is playing some music, and a notification is received, the sound volume will decrease and it will not get back to the previous volume unless I exit and open again the app or keep the volume up button pressed for 2-3 seconds. I know very well how the Attention Aware feature works, but this is not the case.