Siemens WXL167AUK – fills and drains but no agitation

Machine started filling and just didn’t stop. Assumed pressure switch fault so ordered new one. New one arrived and machine now fills, stops and then drains. No agitation. It then sounds like it is trying to bring in more water but nothing happens then screen goes blank and beeps error. Drum rotates as it will spin. Tried on hot and cold washes and still the same. Checked with Siemens and they say part is correct. Any help gratefully received.