No, my C2S PDK does it.

 

Sounds like traction control preventing wheelspin to me.

 

I am not sure what you are doing but to not take it over 2000 rpm you must be lugging the motor and the manual specifically says not to do that, if you went past 4k you or the car would not die either. If it was cold out when you did that the tires could be spinning. The p zeros do not like the cold at all.

My car will spin the wheels on a 20 mph downshift if it is cold.

 

I thought I had a PdK surge on my 09 C4S just over a traffic bump at low speed with mild throttle input. Revs went up maybe accelerated;backed off throttle input; a bit unnerving .Auto:normal. Hard to replicate but brought it into dealer(CPO). They reprogrammed the PdK . Hasn't happened again but was unable to reproduce anyway.

 

The almost instant downshift to the lowest gear you're talking is found on any dual-clutch auto. Any pdk does this, not unique to the 991. Some audi does this too, I did try on an A3 loaner they gave me for a few hours. Single-clutch takes a little longer.

 

After 10k on my own machine, my two cents is not to keep the car in normal auto mode when hitting the curves. Go to Sport, Sport Plus and/or full manual mode. I concluded that normal auto to me is like a Prius mode for slow, boring city driving or driving on a congested highway, in which I know I'm not going to hit the throttle in any meaningful way. When I'm on an open, light traffic highway or twisty road at a minimum I switch to either Sport auto or fully manual Sport Plus. Sometimes I will do an auto normal or auto Sport mode, but while in those later two modes I will do manual downshifts for better control and well hahaha 'cause I love the sound of that engine on downshifts and engine braking. I found for me that trying to hit the throttle while the PDK computer is trying to act in a responsible fuel efficient manner is spending mixed signals to the car on what you want her to do. Oh, and stop babying her. She's German and Schwäbisch. Push her around and let her know who is in control.

 

Make sense on dual-clutch auto, but not all downshift without accelerating when you blip the throttle slightly, especially on single clutch auto.