First, congratulations! That is quite a transition, and you should have seen some differences in how your clothing fits and/or some weight loss. However, I think a little more data is needed from you before we can guess the reasons why you haven’t lost weight.
Did your trainer use the same method to measure your body fat each time? If two different methods were used they will read differently. That could be one reason. Also, how heavy are you lifting with weight training?
It could be a variety of factors or error.