Engine 2.2dci 66KW jerks in the lower speed range

Hello dear forum, this is my first post here, but I’ve been reading with you for a while. I bought a Master 2.2dci 66KW in April and was really satisfied. The first problems started when he started to jerk at the cold start. This was actually always gone when the engine got warmer. I drove to the workshop of trust and it made the LMM new. After that everything went well. Two weeks later I drove on the motorway with full load (130km/h) and the engine went into the emergency run, the ignition lamp turned on and I could only roll to the right. Just waited, restarted and everything went again – but I also drove much slower (110km/h). The next day in another workshop the fault memory was read out and it came: Then I drove back to the workshop of trust with the same list as above. On the way there he also hit the highway at 110km/h. Now he was in the workshop for a week, the e made the following new: The workshop called me and told me I could pick him up. Then I went and wanted to go to the next gas station. Car immediately jumped on and first/second gear everything was great. When switching up into the third again: Ruckle without end. Fourth gear also, but always only at constant speed. At fluctuating speed no jerking was noticeable. Then back to the workshop, car left. Now the workshop manager calls me and said he knew Is there any idea of what the problem could be? Best regards Hannes