Regardless of the LED, We would advise that you test out whether moving the Wireless bass module to another position closer to the SoundBar solves this problem. If so, we may have an interference issue as mentioned.
If not, and the issue stays constant across all sources (both wired and wireless) on the system, then we may need to investigate a potential hardware problem. In that case it would be best to contact your local Bose service group directly.
In the USA you can call 800-905-2156 - Hours are M-F 9am to 9pm EST; Saturday 9am-6pm --- In other regions you can find contact details by visiting http://global.bose.com and selecting your country from the drop-down menu.