Hi - I have a Montana III 9.5 for a while but was never able to fly it properly and always felt not pressure on the bar due to what I thought was the wind condition (too light) but I tried again last week and I have noticed that the rear lines are very loose without any tension on the bar and kite. As a result, I have to pull with my hand on the line to make it turns

.
I went through all the settings again and again and cannot find where I got it wrong. I am thinking of reducing the length of the back lines but find it not normal for a kite that is ready-to-fly.
If someone can tell/show me how to set up the lines so I can use my Montana as it should be I would appreciate.
Thank you
BTW - I am flying a Beamer 3 5m for some times without any issues