I too can recall having 'problems' with night deck landing with the S76!! But only on One night on One New Platform
It was in my very early days North Sea rostered with a very experience Traing Captain. On the approach to my landing (at a point he could not see the rig) he called 'high rate of descent'.
Upset I did not impress him but I told myself I was there to learn.
A couple of hours later on the approach to his landing I too called 'high rate of descent' exactly when I lost the rig visually too.
On debrief we agreed 1.really black night 2.no horizon 3. high deck4.deck lights were the only approach reference 5. Rig not light up at all!!
I went on to many decks over the years with the 332L and 365 but never had any night approaches that appeared so uncomfortable as that night with the S76.