A Google search brought up this.
Samsung Wallet may require you to deregister your details due to a few reasons, including manual resets, security concerns, or potential system errors. If you've recently reset the app, experienced multiple failed verification attempts, or received a remote reset request, your card details may have been removed. Additionally, system errors with Samsung, your card network, or the issuer can also lead to temporary unavailability or deregistration.
May not be the device itself. I've never had issues with Samsung wallet. I did set up Google on my watch, due to not using for a while. My bank however did deregister.