I have notice that if I am texting a person and say i lay my phone down with out closing the conversation and they text me back I do not hear the notification sound anymore. I have notice this since i have updated to Android 5.0. I have done all the checking with the volume and making sure its turned up, changed the sound to a louder one. Not using any third party software just using the standard messaging program (not Verizon messager) This has started becoming a nuisances since i am missing a lot of text messages. I have googled this issue and have not found a fix for it yet, so hopefully we can find a fix so i can get on with texting. Oh i am running on a Samsung Galaxy 5S by the way if that makes any difference.
Thanks
Derek