My inmate was kicked out of rehab, why was he picked up by the US Marshals?

My boyfriend was out on bond from st. Clair mo federal. He was ordered to do 31 days at Pathways Rehabilitation. He successfully completed that and he did not have a home plan so was ordered 120 at Pathways and to gain employment . He did get a job but because of his mouth was kicked out of rehab. He spoke to his P.O she was ok as long as he kept his job . Then he was had a pretrial hearing. The marshals came and now he is back in st. Clair . Can you tell me why this would occur and where I could find more info. Thank you in advance.