Have you tried tapping the hub name on main page, then Switch to Another hub, select your same hub again to reconnect it. It may or may not ask to select a device.
You can confirm the device it is connected to by tapping the More button at bottom then app settings. Check device name is correct.
Yes you can rename the device from within HE once the app creates it.
If reselecting the hub does not work you can try this (click link for full instructions)