If it’s just no notifications for messages then try this;
# Settings
# notifications
# Scroll to
# Messaging
# Check that
# Block all is not turned on
Also look at;
# Open messages
# Tap the 3 dotes in the top right corner
# Settings
# Notifications
# Check settings
Both of these ways do different things and just because you have the notifications ticked in the messaging app doesn’t mean you will be notified if you have the messages blocked in the main notifications phone settings.
Hope this works for you, it did for me (my wife found the 2 settings were different and fixed it, little smarty :) )