The bug that it fails to connect to the hub is something that started to appear in iOS 14 that some customers have reported. We ourselves have not been able to reproduce the issue so we don't know what could be the cause. We're working on updating the app with some more logging to try to figure out the reason.
For the button that doesn't light up, let's continue the discussion in the support ticket you also sent. My guess is that it's out of battery for some reason.