No audio/vibration notifications when phone is locked

Basically, when my phone (13PM) is locked, I don’t get any indication that a notification has gone through. The notification will appear on the Lock Screen, but I won’t know it went through. It doesn’t matter if silent mode is on or off. The only time I do hear it is when my phone is on and in active use. Scheduled summary is off and all notifications are set to go straight through. I’ve tried restarting my phone, turning off and on the “attention awareness” setting, but to no avail. I do wear an Apple Watch that seems to get them, but as it is on silent, I don’t see the notification unless I happen to be looking at my watch. I have missed multiple important texts and calls due to this, and I really don’t know what to do anymore.