Los Angeles MDC

My wife and I have a loved one who has been transferred from a county lockup in Tennessee to federal custody. For a couple of weeks it showed them as "In Transit". Now I see that he is in Los Angeles MDC. I assume that is for some medical issues, they had asked for mental health assistance and have some other health issues going on. I want to be able to write to them, but CorrLinks isn't recognizing their reference number. I know that they only arrived there this weekend, but does it take a while for them to be able to get messages, commissary etc.?

Thanks for any advice in advance.