After calling "discover my devices" my smart home skill was able to discover devices successfully.
My smart home skill is populating devices from a third party cloud, so once i call "discover my devices" say alexa has discovered 10 devices and after that i removed 4 devices from my cloud and after that i called "discover my devices" again. In the alexa web app the deletled device is marked as offline but in the alexa app still the deleted devices are showing (no indication for deleted devices).
The discovery response only contains valid devices. From the third party cloud only valid devices are given.
In the alexa web app (https://alexa.amazon.com/spa/index.html) User can make out the deleted device but in alexa app user cannot understand it.