Permission switch available after uninstalling the app

Hi,
when i install a new app which requires some permissions, these permission are listed under "System Settings -> Security & Privacy -> App permissions" For example if I install "uNAV", then there will be a new switch in the section "Location" to enable/disable access to my location for the app "uNAV". If I uninstall the app, the switch still remains there. If I install the app again, this "empty" switch will be again associated with the re-installed app. This holds also for switches in other sections (for camera, etc.). Restarting the device after uninstalling the app does not help. My device is BQ Aquaris E4.5 Ubuntu Edition with the latest updates (as of 21JUN2016).