It is possible that the awning fabric has become misaligned in the roller track or the sidewall track. This condition can cause the awning arms to bind when retracting. Assuming that your awning arms aren't bent or damaged, I would try removing the set screws on the ends of fabric where it meets the sidewall groove and slide the fabric 1/2" one way or the other until it closes properly and then resecure the set screws.
I have had to !make this adjustment on two different RVs.