[JC888]

My car has been Alpina flashed for about a year now. Today, on the way home, I received a trans malfunction error message on multiple occasions in normal D mode. The first occurrence happened during rush hour. I was speeding up partial throttle as traffic became lighter, it initially slipped going back and forth from 4th to 5th and then it tripped an error and I was stuck in 4th (I assumed I was in limp mode). The error would then clear when I restarted the car. I was able to then again drive normal until it tries to shift into 5th again, then it slips and trips the error. I am able to duplicate this pretty much consistently since the first error message. As I was trying to duplicate this, it was more apparently that the slippage into 5th coincides with a quick metallic whirling, follow by the the error.

What is even more baffling is that I can manually shift from 4th to 5th without issues. My extended warranty ends on the 25th, I'm thinking of having it looked at by the dealer. I was wondering:

1.) should I have the trans flashed back to stock?
2.) anyone have had this or similar issues?