Can you start your phone in Safe Mode to see if the same issue occurs? This will temporarily disable most third-party apps and allow your phone to run on its most basic interface. To enter this mode, hold the Power button > Hold Power Off icon > Tap Safe Mode. Whilst in this mode, please ask one of your contacts to send you a message. Also, please ensure 'Silent' mode is disabled by swiping down from the top of your screen and tapping on the Sound icon.
If the issue doesn't occur whilst in Safe Mode, it points to the issue being caused by a third-party app. If this is the case, I'd advise you to remove your third-party apps one by one until you find the culprit.
Once you've tested the messaging, simply restart your phone to exit Safe Mode.
