Why is my smart alert feature on my s9+ not working???

[Android Central Question]

Received phone on Friday & switched on my smart alert but its not working at all.

 

[SpookDroid]

Do you have any missed calls or messages from the stock messaging app? IIRC, this feature only works with those (and if you use a 3rd party messaging app, I believe, the stock one doesn't 'see' the new messages).

 

[TMavC5]

If you have a missed call or text. When you pick up the phone, it should vibrate. I hate to reply to a none registered user.