@brian1983; Before getting my current DSG equipped car, I owned four VW’s with manual gearboxes from 2002 to 2020 and they all had slick, smooth gear changes, so I agree with Yusee, notchy gear changes aren’t normal, so take it back to the dealer.
If the dealer tries to fob you off telling you it’s normal, ask to drive another mk7.5 GTI if they have one (if not another mk7.5 Golf) so you can compare it to yours.