added at 1142.4, tightening stops
Therein is your severe giveback issue...
You are using UNREALIZED gain as a trigger to add. Since your trades are held overnight, overnight margin requirement is the basis. In this trade, $1000 UNREALIZED is not even 1/4 of the margin needed to hold an additional contract overnight. If this was intraday trading, $1000 unrealized gain may be more than enough to add one contract. Bottomline... a more robust money management scheme based on the funds needed to carry the type of trade will serve you well.