C5 aircross blue hdi 180 problems exhaust gas cleaning

Hello Ride nen blue hdi 180 since April 19. Until the beginning of 2020 no problems at all. Since the end of January I get at regular intervals about 1000 kilometers the information (motor error exhaust gas cleaning defective, vehicle no longer starts in 1000 km.) now it is for the fourth time in the workshop and it should probably be the add blue pump again. Then now for the fourth time ne new would be installed!!!! The workshop (with which I am otherwise very satisfied) says they are in close contact with citroën and there you know the problem. Citroen in turn probably puts pressure on the supplier of the pump. Does anyone else have this problem? Would not like to withdraw from the purchase contract because I am (except for this problem) satisfied and I find the aircross completely successful. Thank you for your answers