Documents sent to old address

Hello, please I need urgent advise, I applied for leave to remain on flr fp route may 2017, after some may chase up I got an email with tracking number that a parcel was sent to me, my solicitor and I did not receive and thing from HO, however I went to post office to complain and I was told that it as been sent back to Sheffield. I moved house during my application but my solicitor told me that I don’t need to update my details since he received the biometric letter and his the point of contact, at the moment his on holiday, kindly advise on what to do as I have called all the numbers I have to contact HO.