No. Bascially, the moss was mostly dead and it's taking a while to start growing again. Given time, it will grow fuller (though each strand won't grow any more quickly). Plants need a photoperiod and a downtime to stay healthy. What you can do is increase your lighting, (which most of us have discovered is not as high as we think it is) along with your ferts and carbon source. What you can do instead of increasing your lighting is trim all the healthy stands, tie them on to something else, and in a couple weeks you'll have twice the number of strands growing at the original rate.
But, just to check, what kind of lighting do you have, and how high is it above the substrate?