ESAM 3000 - Brewing group positions itself eternally

Hello, everyone,

I recently bought a used search result Magnifica ESAM 3000.B. The machine works fine so far, but when I press the flush button, the machine starts to position itself without actually flushing. The brewing head only moves back and forth.

Here is a link with a video, how it looks like.

https://1drv.ms/v/s!AtoohaWYkKRVhqcc2DTW18CFxRkXWg

Maybe someone here knows what to do?

Sounds either like a defective actuator, brass nut is great.
Or the reed sensor on the drive plays silly.clean it and on the big white gear wheel of the drive are a few magnets, because also clean and try everything, if it works
.

Otherwise open the flap, put something on the sensor for the flap and film what happens.