Display flickers from the CM 5200

I have had the fully automatic coffee machine CM 5200 from Miele for about 3.5 years and have had the following problem for quite some time:
-The display flickers sporadically once a month, so that it is not possible to use it-
must then switch off the mains switch completely or pull the mains plug.
I informed myself that contact sprays can be used because of possible grease formation, because the machine is in the kitchen - I followed everything and covered the machine while working in the kitchen - happens again and again.
Then I got error messages 28- Too much powder in the powder chamber
do not use only this compartment, except for cleaning with a cleaning tablet.
I have a 5 year plus warranty - I sent in the machine - it was said that it is a fundamental problem of Miele - I have already been sent in with the same problem and changed a circuit board. With the success that after 6 weeks this problem occurs again. They said it wasn't Miele. It was just Miele on the outside. Great.
Has anyone had the same problem?

Good evening,

if the warranty period has not expired for a long time, then I would send the machine in again and insist on changing a new display or circuit board again until the thing works perfectly.

Greeting HWS