Why I can't I use the top row of keys on my keyboard i.e. the QWERTYUIOP line

[AC Question]

I have the Sam Gal S4 running ver 5.0.1 When I hit one of the keys in the top line, it selects a key in either the line below or in the "suggested text" line. This happens when txting using either the usual Samsung txting app or Swiftkey, and also any time I use the keyboard e.g. when trying to type a word in the Google app's search line, or in Google Play's search line. This began only about 2 wks ago. It's only a problem in portrait mode - if I turn the phone to landscape, I can type the QWERTYUIOP line without trouble. Looking forward to your help, Andrew.