iOS 9.0.2 & lack of text messaging "sounds"

I know this has been an issue in the past, and I have checked through the forum and online posts at multiple sites to resolve - all to no avail.

After upgrading my iPhone 6 plus to iOS 9.0.2, I no longer have sound notifications for text messaging. I have attempted several 'fixes' listed online for this issue in previous iOS updates, but so far, I have found nothing.

I can tell you the following:

1) My iPhone in NOT on mute

2) My iPhone is NOT on 'Do Not Disturb"

3) I have tried a reset of all network settings

4) I have reviewed my sounds and volumes

5) My iMessage is linked with my iPad Air and MacBook Pro

6) I have performed both a hard and soft reset of the iPhone.

The problem seems to exist that sounds are not played specifically when the iPhone is locked. I have heard an occasional sound when it is unlocked. Message previews do appear on the local screen.

So I am at a bit of a loss. Any help appreciated.