I know a couple of people have had the same issue as me with whereby the AIO drops off the network indefinately when charging at a certain rate (nominally anything above 4kW). I just got tagged on one of the Facebook groups by Paul @ GivEnergy and he's pushed out firmware D609-A609 which has seemingly fixed the issue. I have never been able to charge my unit at 6kW and during my test it worked.
The update will be available by request for now so if you have this issue and want to give it a try please get in touch with GivEnergy via support@givenergy.co.uk or if you're on the Facebook groups have a look at the following thread.
For the more risk-averse it will be available in the portal in due course.