My problem was the same, but I’m on a Mac and it was because of Android File Transfer. These were my solutions:
For a Mac make sure that Android File Transfer has properly connected to see the Android phone’s files. If Android File Transfer is giving errors that you haven’t allowed computer to connect to phone properly, then doing “ionic cordova run --list” will not see your Android phone yet, and you will not be able to run/deploy apk from Mac to phone by doing “ionic cordova run android”. Also, make sure to end any emulators that may be running, this will cause to deploy to emulator by default.