I imported a new 7 min clip into the program but it is only 1 sec in the program.

Run Kdenlive from the command line and see if it spits anything out that's useful.

Possible Workaround 1:
In Kdenlive settings, change the duration of imported images/image sequences to that of the video (maybe a little longer to be safe.

Often used workaround 2:
Re-package the video streams (create a new container). I describe two methods in this post.