[AC Question]

Step1: Go to conversation view with Contact-X.
Step2: Send Contact-X a text message.
Step3: Contact-X sends a reply text message.
>>> I *don't* hear a notification sound.

Step1: Go to conversation view with Contact-X.
Step2: Send Contact-X a text message.
Step3: Go to some other conversation view or some other mobile app view.
Step4: Contact-X sends a reply text message.
>>> I *do* hear a notification sound.

I want to hear a notification sound regardless of whether I stay on the same conversation view or switch to something else. Is there a setting somewhere to fix that? I didn't have this problem back when I had a Galaxy S4.

[ManiacJoe]

This feature is depended on the SMS app you are using. Some do it, some don't.
I use Textra. I eventually found its setting to do that. Not sure how new this feature is in Textra.