I have the same thing going on and thought it was just normal. Things looked to be aligned okay. I've just given it a bit of a kick for it to let go. I thought chain tension just ends up being what it needs to be and not sure how you could reduce that to get correct weight transfer? Lifting the tongue somewhat helps, but usually not enough to for it to drop on it's own.
Have a brand new TT I'll be switching our Reese DC over to and will be paying closer attention to installation details this time.
Would it matter much if someone had more or fewer threads engaged on the arm? (Different angle on the arm) Assuming weight distribution between axles would be okay, could you reduce the angle of the spring bars by changing the angle of the hitch head to help?
Will be interested to see further comments...