Without seeing how the OP was responding to nutrition and training for a while, I can off hand mention a few things:
1- Are you retaining water from the test? Some people can hold a lot of water from various esters, not sure if the gel has similar effects.
2- I’ve worked with a good number of assisted athletes in the last few years, and I’m amazed that I often have to diet/cardio them harder (lower cals, more cardio!) than most of my natural competitors… Honestly, this surprised me a lot, coming in with my science is science approach -lol
One point though. A pound of non-fat bodyweight only CONTAINS about 350 calories (about 80 grams of protein 8-9 grams of glycogen/free fatty acids) while a pound of fat contains 3500 calories. This is because muscle and fat free organ mass is 80% water. Calories in, calories out do not thermodynamically equate to bodyweight changes if there is a shift to fat free bodyweight.
Usually though, building fat free tissue is energetically expensive, but if TRT is shifting the balance to fat free tissue then weight can rise in a caloric deficit.