Openhab Android App: No Openhab 3 UI and No Notification

Maybe this is an issue with your WebView? Do you have https://play.google.com/store/apps/details?id=com.google.android.webview installed and updated to the latest version?

AFAIK Firefox on Android uses it’s own rendering engine, Brave might use the one provided by the OS. The openHAB app does latter.

I use LineageOS and I’m not able to install Web view. But in Brave all other Websites work. And here it load also something, but the result is a blank page.