2019 Rapid 1.5 TDI Diesel DSG sluggish upshifts during uphill ascent , inclination sensor issue ?

I think I see what it's doing now. When you first set off it shifts straight into 2nd and slips the clutch slightly which is what mine does.

Then when you set off on the hill it holds first gear until it can shift straight into 2nd without clutch slip. Hence it revs a little higher.

It certainly needs normal behaviour and just how they've programmed it.

Most likely to reduced clutch slip and wear as much as possible.