Could Not Set Up Apple Pay on Mac

I am trying to set up Apple Pay on a MacBook Pro 15" 2018 with T2 chip running macOS 10.14.6. The startup security settings are set to maximum, and all security updates have been installed. When I attempt to add a credit card (System Preferences > Wallet & Apple Pay > Add Card... I receive a message

Apple documentation indicates that startup security settings could be too low, or that some security updates have not been installed.

I had lowered the startup security settings when I bought the machine new in 2018, but was able to setup Apple Pay anyway at some point. Several days ago, when I noticed this error message, I booted into recovery mode, started the Startup Security Utility, and could not get past an error message that no admin account was found on the startup volume. Since then I have been trying to resolve that issue, and succeeded by erasing the boot volume and reinstalling macOS in recovery mode, then migrating user accounts and data, and applications and setting from a backup. That having worked, I was able to change the startup security settings, so now they are maximal. I also installed all security updates that were missing from the clean reinstall. Nevertheless, the message still appears.

Has anybody encountered this problem before?

I notice on iCloud.com in my Account Settings that Apple Pay is still configured with the credit card that I am attempt to add to the wallet on the MBP 15".