For the first couple of days with the Cosmo Communicator, the purple LED above the camera was constantly on. The quick start guide says this LED light is a 'Wireless Indicator LED'. Additional details on when this LED comes on/off is not described in the guide.
The purple Wireless Indicator LED went off after I figured out how to get T-Mobile (US) Mobile Data working. Apparently, the inability of not having Mobile Data working was causing the purple Wireless Indicator LED to be on constantly. The Mobile Data option in the Android settings was greyed out and unresponsive when tapping on it.
So, what did I do to get my T-Mobile Mobile Data working? I consulted with a T-Mobile representative who directed me to the following
BYOD T-Mobile data and APN Settings webpage.
After locating the Access Point Names setting in Android 9, the APN settings matched to what is on the T-Mobile webpage except APN Type and APN Protocol. After changing the APN Type to default,supl,mms and APN Protocol to IPv4/IPv6, I was able to turn on Mobile Data in the Android settings. It was then I noticed that the purple Wireless Indicator LED above the camera on the Cosmo was off.
Perhaps the Wireless Indicator LED warns the phone user/owner when cellular data is no longer available?
Note: It seems enabling/disablabling wifi has no effect on the Wireless Indicator LED.Cheers!