Efile Error Code 108 - Express NOA

I just tried filing my first return where client wanted me to receive NOA on their behalf. I completed part F accordingly and filed return.

When I go to download the NOA, CRA presents the following error message after I log in.

The client has not authorised electronic receipt of the Notice of Assessment through this service.
Part F of the T183 must be completed.

But I did complete part F properly. Anyone else having this issue?

Likely due to the fact returns are not being assessed yet for some unknown reason. Check RAC and see if anything you have sent has been assessed? Express!