I'll preface this by saying I'm not in a panic or worried much at all. I'm happy with where I'm at and know that it's going to be 6-12 months before I see much in the way of positive results. Nevertheless, I am curious.
Prior to this month I was only an AU on a few cards. I have multiple derogs, many falling off this year, a few that are not. My scores were sitting in the very low 600's. I decided it was time to start actively rebuilding and acquired two secured cards, Discover, and Citi Diamond.
As those cards hit my reports, my score is dropping. On February 14th, the Discover card hit my TU. My score dropped 70 points. MyFico shows my total bankcard limit has increased from 57400 to 59400 (the AUs are the bulk of that obvsiously). New score: 564
Citi Diamond hit my reports today, increased bankcard limit to 60400, score dropped 4 points. MyFico isn't even reporting the Citi card itself in my notifications, it just shows the bankcard limit increase and the score drop. New score: 560
I appear to be worsening my situation. 
I'm well aware that it will be a few months before the payment history helps me. It does seem odd to take a collective 74 point hit for increasing my total limit and having two cards that I'm primary on.
Anyone want to take a stab at the whyforwhatnow?
Depending what your age of youngest revolver was (AOYRA) if those AU's were counting you likely reset that and possible changes to your AAOA which is what sounds like what happened just based on score magnitude when the second one reported.
Also if either of those did report with a balance that might twiddle things too.
Anyway you did the right thing getting your own tradelines and establishing positive personal history is absolutely one of the critical steps in any rebuild.
