In case you're checking in on the app, I found when this happened to me that signing-out, force-quitting the app, and signing-in again worked. Others in my party needed to restart the phone as well. (All on iPhones.)

As that worked, if you're seeing this on the web, it may well be that signing-out of your account and back in again will fix it.

Obviously, no guarantees as we don't know what's actually causing the problem - but it's certainly not (in most cases) anything wrong with travel documentation.