Apple Wallet app "Restricted" after enrolling in Apple Business Manager

We're in the process of moving all our employees Apple ID's off of our domain to create a new Managed Apple ID for each of them, by changing their Apple ID to an unused domain of ours, then signing back in with our Office 365 credentials (logins are federated).

One of our users has reported that since we made the changes, they're no longer able to access the Apple Wallet app. The icon is missing from the home screens and when you find it in the App Store and press Open, is says "Restrictions Enabled".

There are no restrictions on the device and I'm utterly baffled by this.