Skoda Rapid Tempomar acceleration issue

Hello Everyone, 

I own a 2014.11. rapid spaceback 1.2 tsi, 105 bhp, 6 gang.

Last year I decided to install cruise control, which I was unable to do by myself (BCM replacement needed and because of programming), so I found a mechanic here, in Budapest, who is well known in VAG community for using only genuine parts and for his professional attitude. What I want to say, is that I wasnt trying to get the job done for cheap:) 

Everything was perfect until yesterday, when I tried to accelerate from 130km/h using the buttons on the lever. When I reached 135 km/h the tempomat light switched off, the gear icon from the multidot disappeared also and I felt a slight kick, which is comparable to a bad gearchange.

The second time, I had the same issue, but to be completely honest, I wasnt smart enough to turn off and on the tempomat on the lever or to restart the engine. 

Accelerating from 40 kmh to 80 kmh is just perfect, no problems at all. 

The serviceman, who dod the programming and the installing said that problems like this may occur if the gearbox is replaced, but every part of the car is original, it is being serviced at the dealer every 10k kms. 

Did any of you experienced issues like this, what might have gone wrong? 

Thank you for your help in advance!