When BluetoothLE device connected, I switch to "Discover" page. The connection won't be released.

[yijenlu1971]

Which sample are you reporting a bug in?

Example: BluetoothLE

Describe the bug
In Discover page, select a BLE device. Switch to "Client: connect to server" page, then connect to it.
The connected device shows "services" "characteristics"... Read value.
When I switch back to Discover page, then press "start enumerating".
Can't see the BLE device in the list box. Seems not to release the BLE device.

To Reproduce
Steps to reproduce the behavior:

1. In Discover page, press "Start enumerating" button. Select one BLE device.
2. Go to "Client: connect to server" page, connect to the device.
3. Select one of services, and select one of characteristics. Read value or write dummy value.
4. Go back "Client: discover servers" page. Press "Start enumerating" button. The device won't be disconnected.

Expected behavior
When I exit the page "Client: connect to server", the device will be disconnected.