You have to send "?r" to get a return, how utterly stupid.
There is a very good reason for this behavior and it relates to how the Hitachi controller works.
As you are probably aware, the controller has the ability to store 8 custom characters which are accessed with the codes 0x00 - 0x07. If you look at the character set you will see that the next eight hex codes (which include your desired and ) mirror the first eight codes.
This means that if you were to include a code of 0x0D in the ASCII string sent to the LCD controller by the serial backpack it would display the custom character #6 stored at 0x05.
Other than that it is a very good board, but I feel that is enough of a flaw that it should NEVER be used.
So what you are saying here is that the LCD controller itself has a flaw, since it does not 'properly' interpret and , and therefore it should never be used.
Actually you have to understand that these devices were never intended to be used in the way that a computer screen is used, to display large amounts of text spanning several lines or pages. They were designed to display short messages such as "Add more paper", "Your Pizza is ready", Your garage is on fire", etc.
Don