PS4 playing on a 56" TV. I tried sliding the UI control, but it only had a tiny fraction left to work with. So, it didnt make a noticable difference when I moved it. My setup is playable, but about half of the buttons are off-screen that are on the edge of the UI. I checked my TV for settings. Couldnt find any for resolution. Must be automatic. Its only a few years old. 1080p capable.
EDIT:
THE FIX for PS4 and TV display Users: I had this same issue and after much poking around on game settings (UI slider), and looking for TV settings (didnt help), I found a setting in the PS4 settings that I never have had to use before. You can do this while in-game to get it just right by hitting the PS button while in the game and going to the PS4 SETTINGS/SOUND AND SCREEN/DISPLAY AREA. Adjust as required and reenter the game. Works perfectly now.