Gearbox issues

[gustav]

I own a c5 2.2 auto crosstourer 2015.
Today a workshop replaced the right driveshaft. When I picked up the car I noticed that when I put it in drive from park it's like the gearbox is hitting drive hard. Not smooth like before the driveshaft replacement. Putting from park to reverse is smooth as before and the same for all other gears when driving. According to the workshop this is due to worn splines in the box? They showed me the old driveshaft saying look at this splines. This is the culprit.
Is this valid? If not, what could have caused this?

[xantia_v6]

I am doubtful of it being the splines, even if it were the splines, it could just as easily be that the new driveshaft has wrongly machined splines. Did they put the car on the ramp and show you the play in the splines?

BTW, why was the driveshaft replaced?

[gustav]

Nope, they only showed the worn splines on the old shaft.
Shaft replaced due to a bad joint.