Lowrance is aware of this bug and they are working to resolve it in the next software release. In the mean time they offered a couple of suggestions on how to deal with it now.
1) If you have the LWX-1 Sirius installed and no SonicHub and want to be able to continue to use the Sirius audio: Right now the only option is to mute the audio. To do this with the Sirius pane active (highlighted) press menu and select mute.
2) If you do not wish to have audio features enabled at all there is an option for that as well: Press Menu>Menu>System>Advanced>Features>Sonic Hub. Now the SonicHub features are enabled and you can turn the audio bar off via the normal process: Menu>Menu>Page>Audio. *With the SonicHub features active you will not be able to control the Sirius radio without having a SonicHub installed.