Radio (infotainment) stays on after exiting vehicle **now window motor issue per dealer**

Today my infotainment system stopped turning off when I turn off the vehicle and exit.
Have tried a few things including:
removed USB drive with music
disconnected cell phone
removed vehicle profile
tried opening & closing all doors several times (see below)*
called onstar for remote diag. (nothing helpful)
disconnected battery for an hour

*As a side note, the dome light does not come on with the driver door during this problem but does come on with the other three doors & hatch. And when the radio does eventually time out (10 minutes I think), the drive door does activate the dome light. So it does not appear to be the physical door sensor.

None of this helped, so off to the dealer I go with my two month old Blazer with 1200 miles. :-(
If anyone has any ideas, feel free to post.