If by chance your newly introduced TRT is converting to Estrogen that might explain the fat. So if that is the case I have heard Zinc can help block Estrogen.
I am in the same boat as you. Been on TRT for 6 weeks and up a few pounds, but strength is up as well. I am going to give it a few months before introducing Zinc in to my diet. Will also get some blood work done to see what has changed.