and my solution which was posted by someone else and is very similar with respect to your solution was posted here:
The issue boils down to iOS 9.3.6 not supporting certain modern browser features such as the level of JavaScript required to run Lovelace. Installing a different browser on the iPad doesn’t change anything because those browsers all use the base webkit installed in iOS to function. so Firefox on an iPad is essentially Safari webkit with a firefox wrapper. The HA iOS Companion app is more or less a glorified web page with extra background features and functions.