I have same problem, some browser can fix by
var settings = new {
WebViewVisible = true
};
var json = Global.ZennoLab.Json.JsonConvert.SerializeObject(settings);
instance.DroidInstance.Settings.SetLSPosedSettings(json);
or appium settings green brick, but some browsers can't. If all android no have tree of elements, not only browser, maybe need reset phone, before I had problem with elements even in all android apps, fix after reset factory