Thank you for taking the time for your researched response. TL;DR -- 'immediate' charging opts do not work; car thinks it's charging as I can't take it out of Park.Speaking of things that many of us probably didn’t know that are discussed in the owner’s manual:
Have you read through your owner manual’s section on Charging Status Feedback in the Driving and Operating section? For my 2012 Volt, referring to the Charging Status Indicator, or CSI (i.e., the little light on the dashboard), it says "If the vehicle is plugged in and the CSI is off, a total utility interruption using OnStar or a charging fault has been detected. See "Utility Interruption of Charging" or "Charge Cord Status Indicators" later in this section." This section of the manual has a longer description of Utility Interruption of Charging, triggered via OnStar. It could be the driver's display is reading "Charging" because it's ready to be charging once the utility interruption is corrected.
Also, have you turned on the car while the charge cord is plugged in and reviewed the energy usage center display regarding the "Charging" selection? Here is where you can see your delayed starting time and expected completion time when you don't override it. I should think that if the driver’s display shows "charging," this display should also show that same status, unless (as in my manual under Instruments and Controls) it is showing a Charging Override/Interruption Pop-Up message. It appears that one reason for such an interruption is "The charge process was interrupted by the utility company via OnStar as authorized by the vehicle owner (available in select regions)." OnStar has been behaving oddly recently it would seem from the number of postings I’ve seen... Could it be playing around with your 2011 Volt?
Also, if the cord is plugged in and the car knows it, you shouldn’t be able to drive the car until you unplug it. Can you? That is, will your car allow you to start it and shift out of Park even though the cord is plugged in and the driver’s display reads "Charging"?
I did read the manual from cover to cover before I got my Volt and while waiting in airports to fly to NY (from IL) to buy it back in Feb'11. Volts were not available in IL at the time. That was a while ago so I don't even recall that utility interruption topic. I read sections, Steverino's FAQ and hundreds threads daily a few years back but don't go to the manual much now.
Since the CSI goes from yellow to off vs yellow to flashing green (delayed charging) it would seem the handshaking/confirmation and charging procedure did not complete. I find it odd that the system does not detect that since it is such a core part of this car.
Originally I was using the option of rate ('off peak') and delayed charging (7am) and it has worked for literally years. I use it because I'm on an hourly rate plan and my rates are cheaper at night. When I first noticed the problem I waited until about 9:30p to see if the charge added any miles as it starts at 9p. It didn't add any miles. HOWEVER, since then I tried playing with the times (no joy), forcing immediate by unplugging/plugging in a few seconds (no joy), and changing the charging section to do immediate instead of delay&rate (no joy). NOTE: this charging area does 'think' it is charging because it gives me an estimated completion time.