Rebalancing Simulation

I am running a simulation with a rebalance and reconstitution every 3 weeks. I am using dynamic weight with an ideal number of positions of 15. My sell rule is sell when rank<90.

My portfolio had 5 stocks, with approx 20% weighting each. During the reconstitution/rebalance the sim triggered a buy, with no sells. It added a sixth stock to the portfolio, with a weighting of less than 1%.

I am trying to figure out why it didn't reblance to bring it more in line with the other five stocks?

Would you mind posting your trading system? Dynamic weight rebalancing can present challenges like these, but without seeing the parameters, I wouldn't be able to diagnose the problem. Go to your system, click on the "Trading System" tab, and post a screenshot, please. Feel free to black out anything that you're worried someone might copy.