Janelle,
It sounds like you have a tuning problem or the bar & lines is not the right one for the kite.
The middle lines shouldn't have any or much slack so they may be too long.
With the bar out the rear lines can go slack. If they are tight but you have delayed response from the kite that is not good.
I would take your setup to a trustworthy kite shop and get them to check the line tuning and lengths.