can't resize my dial pad in my phone window

[Syed Abdullah Mannan]

Hey Guys,
This might sound a bit silly to some of you but i am having an issue with my dial pad. I recently got my s6 edge plus, when you hit the phone icon in the dock the dial pad comes up resized (see attached), i have tried everything but no luck including web search.
I have even tried pressing the home button thrice which switches the screen into one-handed mode and the dial pad then fills up the one-handed screen but comes out of it just like how it looks in the picture. Could someone please help.

 

[V J]

System Settings > Display > One-handed operation > One-handed input > toggle that off