I floored my tuned stang at a light and shifted hard at 3k rmps. I let go of the gas and then press it and it was just rvving but barely going the green tire traction control came on if that narrows it down. I then braked completely and then it accelerated normally.
I'm not sure what constitutes shifting hard at 3k rpms...
It was most likely your traction control bogging the car down, especially if it accelerated normally after you stopped. You probably just need better tires. You can turn off traction control and try it again just to make sure. If it does it again, then we can start looking for other issues. Just make sure you have space in case you completely lose traction.