fr valve stuck closed ???

ok had a few faults with eas on my m reg 2.5 d rr some times all works fine up and down no problems ....

and the next day suspention takes long time to rise after being on motoway.. showing normal on dash but very low then up as normal

then MAX 35 MPH fault reset fault s show fr valve stuck closed any idear what is wrong

after i reset all is ok suspention set to normal

any advise please