Siemens EQ6

Hello,

I gave a problem with my EQ6 Extra Class and no longer know what to do.

The following happens:
The "Clean milk system" is not finished and gets stuck in the last process step - blowing through with hot air - and can then only be canceled by unplugging.
After restarting, the error message "Refill non-carbonated water or change filter" is added (I have no filter and of course only still water ) and no water is delivered.

After a while, the machine then usually just works again, coffee and espresso can be obtained without any problems.
Problematic is only again when dairy drinks come or when the system is cleaned.

After Internet research, I was already active, have checked flowmeter and replaced the ceramic valve. After the exchange, the error was a good week disappeared, nu he is back

Vlt has one of you still ne idea, I'm a bit at a loss.

Thanks in advance,
Happy Easter
Greetings
Steffen