Samsung Galaxy S5 running android 5.1.1 when I am in text messages

[AC Question]

When I am in a message and tap a picture to see it full screen, I can't go back to the message. I can't go back to messages at all. The picture has a save icon in upper right, but no other option to reduce/get out of the picture. I can't get the image out of full screen mode without shutting down the phone and restarting. I can hit the home button and get out of messages and do other things, but if I go back to try to look at any messages, the picture is still on the screen. Is there a fix?