No notification sounds on iPhone 8

I have an iPhone 8 connected to my Apple watch (v2). My iPhone will not play notification sounds when the screen is locked. It will however, play the notification noise when my screen is un-locked. The left toggle switch is not switched down, do not disturb is not on, and any other resolution you can Google has NOT helped. The text message notifications come through on my watch which is set to "mirror" iPhone.

I reset my settings and just updated my phone to 11.4.1 and my iwatch yesterday, and it worked briefly.

Thanks for any help or suggestions.