I attempted to write my test today and also received a similar error message. My invitation was granted on April 28th as well.
I want to surmise that there's an internal error OR that invitations-to-test date eligibilities haven't yet caught up. Either way, I lodged an email to the address provided in the official Invitation letter, so hoping they work quickly.
I want to surmise that there's an internal error OR that invitations-to-test date eligibilities haven't yet caught up. Either way, I lodged an email to the address provided in the official Invitation letter, so hoping they work quickly.