Apple Pay Disabled because of security Setting of this Mac were Modified

I found another way to fix this:

Create a 2nd user. Use the same icloud account. Log into that user, and go to system settings/wallet. Try to add, and you'll get something saying that another user on this mac is using apple pay, do you want to delete the cards. Say no.

Log back into the first user. Go back to the system settings/wallet and try to add again. When you get the "do you want to delete", say yes. Then add the cards.

Awesome solution! It worked like a charm. I spent over an hour with a senior Apple rep with no solution. He finally suggested that I wipe my computer and reinstall. Glad I didn’t. 👍

Creating a 2nd user worked like a charm! This was such a nagging issue after I had to go through a whole Apple ID password reset a few days ago. All set now.