Siemens EQ6 brings FI switch

Hi!
My EQ6 knocks me out overnight the FI switch and no, it is not leaking.
I have so far found out the following: pull off the plug on which the two sensors of the heater go, the machine goes on, but brings the message with the hotline.
Is also understandable, but what confuses me is, I measure at the two parts neither a ground fault nor a short circuit of the sensors. Both are so between 60-70 Kohm.
The lower sensor is firmly connected to the heater, so I will test whether I can reduce the error to a sensor, unless someone already has an idea.
Greeting Eggie

Hello,
we also have the problem with the FI switch on an EQ9.
In our case, however, the RCD only trips after a few cups .
However, the machine does not show any leakage.
Have you found the fault in the meantime?
Greetings