Unable to link card to apple pay

I was making back to back purchases using apple pay, the first being successful while the second failed.

Checked apple pay and it said there was some verification issue and I had to verify my details or something. Tried to edit my billing information and all but it would not save.

Got fed up, came to search the discussions and saw some recommendations to remove and add the card again. Did that and now I keep getting the same error message: "There was an error. Please try later."

And before anyone asked me to refer to If you can't add a card to Apple Wallet to use with Apple Pay - Apple Support (SG), I have already done so and my issue is not related to that. I am still able to use the card in my apple wallet to make purchases.