I had the same issue. After the 18.1.1 update I was receiving text messages, but not getting notification, my issue was "hide alerts" was turned on for each person that I received a message from. I had to click on the message, then click on the persons name on the top of the screen, hide alerts needs to be slide to the left, if it's to the right, then you will get the message but not the alert. I had to do this for each individual person sending me a message. After I moved the "hide alerts" to the left, I've been getting a tone notification again. The group text messages were not affected by this update, the "hide alerts" stayed in the off position. I hope this helps with your issue. T.