Samsung S7 - sudden wallpaper only screen and can only view notifications

[TheEdward]

So I got a replacement S7 because I dropped my last one and it died. Now every now and then, everything will close and it'll go to a tad stretched out wallpaper. There will be no more app drawer or other shortcuts. I can only lock and unlock the screen and view the notifications. I can't open settings or interact with the notifications. What might be causing this? I am using the Google Now launcher. No other adjustments or changes have been made. I have to restart my phone to get my app drawer and stuff back. I'll include a screen shot. Thanks.

 

[chanchan05]

The center button there white circle with dots should be the app drawer.