Thank you Jianye and Yanni!
I had a problem with the battery - it would go to sleep when the charge was low, which is fine. BUT it wouldn’t wake up again when there was available solar or when I wanted to charge it from the grid. I was having to go outside and switch it on manually - that is NOT fine. The house and system are just six months old but the issue only became apparent in autumn / winter. I rang Growatt support and an engineer, Yanni, got in touch by WhatsApp within the hour. He tried a few things over the course of a week but no joy. So he arranged for Jianye to visit. He changed communication ports, left for the day but still nada. He came back the next day and changed the Battery Management System and eureka - sorted! It took about 10 / 11 days of back and forth but it was a huge relief to have a working system and I’m grateful for these guys’ persistence. I’ve dropped a star because I feel the brand new kit shouldn’t have gone wrong in the first place.