Sketch up for Schools - keep receiving 'needs permission' message on login

I have been trying to set up S.U. for schools via our local authority. I received a confirmation email from our local authority admin to say Skatch up now has permission and I can download and login using my Microsoft/school email.
However, when I downloaded the app and used my credentials to log in, I still received:
permission message
Our business manager is in touch with our local authority but as yet we don’t seem to be able to solve the problem. Can anyone help?

@Steve_Ketchup ideas?