MacBook Pro M3 and Dell QE2723 Ultrasharp monitor settings

Hi- I have a week old MBPro M3 and a two day old Dell QE2723 monitor. My MacBook Air connects seamlessly with the new monitor but my MBPro has issues resolution-to access the dock at the bottom of the screen I would normally scroll down but with the MBP I have to minimise the screen.

Settings I understand from a really good, I thought, YouTube were to keep resolution at 2560/1440 and refresh rate at 60hertz. But when I get to preset in settings it comes up as an Apple Display and refresh rate is Promotion?? I spent an hour with Apple support chat and they mentioned it was the cable responsible for this- it's the standard USB-C Dell supply not one with a lightning graphic.

Can anyone offer me any advice re-settings etc? Many thanks Mark