Based on your phone model number, I gather you're a Verizon customer with an Galaxy S5?
Are you using Message+? If so, that's the issue. Stock Samsung message app works, but some thrid-party and carrier specific apps will only show the message your're seeing.
If you're using the stock app, check to see that "Preview message" is set to "On" in the app settings. Not sure if it's the same as the S6, but if so, select "More" then "Notifications" then "Preview message."
Best Answer