Yes, correct first time. Which would coincide with the problem rearing its head. So just hold on for an update?
At least I know and it won't drive me mad now. Thanks for your help!
Yes - there is a known issue we found during the iOS 12 Beta releases, which is likely to impact the formal release as well. I've created a post here: https://community.bt.com/t5/BT-Devices/Whole-Home-Wi-Fi-App-with-iOS-12/td-p/1880482
I will publish on that thread when we have a confirmed release date for the new app.