I have a wifi rear view camera in my car. That camera creates a WIFI hotspot for my phone to connect with. If I put my car in reverse the app gets notified and switches to the app to show the camera view. But if i'm connected to the hotspot my phones internet doesn't work (duh) because the camera doesn't have any internet access.
I only want wifi for that specific app and my phone should use my 4g data, but I don't know how or if it is even possible.
My phone has android 9 and is rooted. Is this even possible? Because I read that on IOS this works by setting a custom dns (or something)...
init
trigger, or listening to some uevent, or using some automation app) to get desired behavior, provided that WiFi and Mobile Data are turned ON at the same time (check "Mobile Data always active" in Dev Options).