Do you still have relaxed ends? What's your regimen like? And what products are you using?
I had the same issue and still suffer with it to an extent, it's possible that if you've used heat while transitioning your hair you could've damaged the curl pattern which would be why one side hangs lower than the other.
Now what I did was start the CG method and my hair started curling tighter on the other side. I just basically baby my hair and although I still notice that its uneven others can't. I've just chalked it up to getting a trim at Devachan within the next month or so.
last relaxer; 082708, BC; 081810, CG; 122410
high porosity, med/coarse texture, high density, color treated