DCT shifts empty

Hi!
So, this is my last try to find a solution for my DCT Problem.

Apparently there are no Twin riders in Germany knowing this problem (Honda doesnt care),
but I got the same answer every time.
"Clean your shifting motor"

My bike had 1800km on it, when I bought it last year.
First it was all fine, but after maybe +300 km I noticed that the DCT tries to shift from 1st to 2nd gear,
and will not engage at first try.
It got worse till I wanted to ride to Italy. It tried three times to shift into second gear, then it engaged.

I searched for this issue in some forums and cleaned the shifting motor, right before I rode to Italy.
It had lots of coal residue in it, which shouldnt be normal with this low age.
While riding my bike through Italy I had the first shifting failure at about 1500km after cleaning the motor.

I let it be for the next 3000km and it got so bad, that it tried to shift 3 times every time between gear 1 and 2.
It also appeared between gear 3 and 4 now.

A friend of mine has the absolute same bike and borrowed me his perfectly working motor to test it.
It worked finde, because I cleaned it as well, but there was a failure to shift too.
He never had one single problem with that motor in his bike.

Last week I made an oil- and filter change with Motul 5100 10W30, cleaned my miserably working motor again (there were kind of big chunks of coal in the Motor after the ride to Italy) and hoped that this will change something, but it didnt.
The bike runs better, but since then I had 3 failures of shifting after only 200km.

So here I am... What could cause this problem, if not the shifting motor?

I´m really desperate and I´m considering to buy a manual bike, to change all my (optical) modifications to the new bike and sell this piece of junk.

Hope you can help me with this...

Best regards
Tim