You’re between a rock and a hard place. It takes the co-ordination of both support teams to adequately resolve the issue.
You can try this. I’ve read on other social media platforms that Goldman has the ability to remove a co-owner and not close an account now. This only happens when the co-owner is not setup properly. Normally, removing a co-owner results in automatic closure of the account. If you can get to a high enough level of support you might be able to confirm if Goldman will/can do that. If they indeed have to close the account, they will be the only way for a quick resolution of the issue.
Let’s run through some settings and lets see if anything pops up.
Confirm your region is set correctly.
Change the language and region on iPhone - Apple Support
Change your Apple ID country or region
Update the birth date associated with your Apple ID - Apple Support
Having you ever changed your Apple ID? Have you changed the email address associated with your Apple ID?
Is your iPhone on the latest iOS? Is the other co-owners iPhone updated?
Update iOS on iPhone - Apple Support
Turn off VPN
Reset Network settings
Remove all credit cards from Apple Wallet on iPhone.
Log out of your Apple ID.
Delete the Apple Wallet App.
Do a forced restart. Follow instructions to the T.
Force restart iPhone - Apple Support
Sign into your Apple ID.
Download Apple Wallet app from App Store.
Try adding your Apple Card account and making a transaction.
How to add Apple Card to your Apple devices - Apple Support