AISIN 6 gear automatic transmission issue
 

I have Mini Cooper S, 2005/11, with an AISIN 6 gear automatic transmission and 65,000 klm so far. I bought it few days ago.

Before I buy it I took it for a full review from an authorized local service / dealer, who verified to me that the car has no issues. I also performed a short test drive myself.

Nevertheless, from the very first day I took over ownership, the car after warmed up for few klm at some point is shifting into neutral and is not responding to paddles or gear orders. Few seconds later, it is changing gear normally. Last time, this happened however, I got an EP indication.

I towed the car to my local specialized (not authorized) service and since then we are trying to find out what is wrong. Take note that the previous owner has changed gearbox fluids (Febi / Bilstein) 5,000 klm ago and he claims had never experienced similar issue. Also nothing identified in the car's log.

Any ideas?