Mini boxes not working - Programme Unavailable

[Kevin6708]

Sky Q was installed in my house 5 days ago, main box plus two mini boxes. After 3 days both Mini Boxes started showing "Programme Unavailable", despite being connected to the main box.

I've been through all the reset procedures but nothing solves the problem. Sky helpdesk (chat) can't resolve and are saying 4 weeks before an engineer come come out to resolve which is completely unacceptable.

Any ideas to resolve?