We're trying to integrate with Google Pay for Passes to add transit tickets to Google Pay, using C# and the "skinny" flow as described here: "Skinny" JWT variation
We're also using the C# example as provided here: google-pay/passes-rest-samples
The REST calls for transit all succeed and the JWT token is generated, however when trying to add the ticket to Google Pay by using the link "https://pay.google.com/gp/v/save/{jwt_generated}" it just fails with a generic error saying "Something went wrong. Please try again later.". We've tried by just using the link directly, by adding a JS button on a website and even tried loading from a native android application, they all come back with the same error. When using JS button, the error callback returns "SERVICE_ERROR" with no further details. On google console we can see the transit class status as APPROVED.
Any details on what we might be missing would be helpful as it's not clear where the problem is originating from.