In App provision failure "could not connect to Apple pay"

During our testing of in-app provisioning on the Apple Wallet we receive the following message from the wallet "could not connect to Apple pay". This occurs after we have accepted the T&C's and have passed the encrypted payload from the banking app to the wallet. No other information about the failure is given. We know that our process for generating the payload is correct. The problem only seems to occur on later model IPhones, 10 and above.