A few people I notice having similar problems but I wasn't able to respond.
I downloaded google pay to see if I could add the card and it asked for CVV or similar. I typed it in and it said "must be four digits".
Went back to Samsung wallet, scanned card, and entered four digit number on the front of card - Budabing-budaboom, it worked.
So not the three digit code on the back, but the four digit on the front, just above the last part of the long number and next to the contactless symbol. The "next" is then able to press and is not greyed out.
I then received a confirmation email confirming the card had been added.
