If you have access to another device, test it.
You could log out and authenticate Project-GC again. I can not see why it should fix it, but it's an easy test.
We are not aware of any changes made that should cause this, and haven't seen any other reports of the issue. This makes it hard to fix, since it's likely to be a local issue.
Most likely fix is a hard refresh, but I am not sure that is possible with iOS.