Water Weight Gain? E2 in Check

So I am on 200 mg test ethanate for 3 months. I do monthly bloods and e2 is in check. Use arimidex however when I take a shot, next day I weigh 3-4 lbs more. My doc said might be the ester and could change it up if I’m holding that much. Also dhea is going down in range and might have to supplement dhea? Is that a known issue with trt?