All 4 of your lines have shrunk, so when you replaced the steering lines, they would be a tad longer, depowering your kite.
You can fix this in multiple ways:
Make new knots for the steering lines that are a tad shorter
Add new centre lines
Stretch your current centre lines
Add extensions to your current lines
See if you can tune the lines at the bar, I know I had to do this with my old bandit - there were 4 or 5 knots on the steering lines i could adjust to compensate for line shrinkage.
All of these fixes simply even out your line lengths, there is a video that describes that here:
Let me know if this doesn't help