🤔🤔 A couple of thoughts, in addition to Oregon Campers thoughts, for your consideration. You,ve probably looked into these already but are offered here. 
(1). Looks to me that during a rollout or roll in operation the extension arms got out of alignment on one end while the other extension arm continued & twisted/stressed the fabric?  The “flap portion tore along the kedor strip & got folded in on itself when it was being rolled up ?
(2).  Did the awning ever get all the way out &, reverse itself & start rolling the fabric backwards? 
(3). Have you checked for any mfgr. R recalls by your VIN# ,,,,,put in vin, model #, Mfgr. & will give you a listing of any mfgr. recalls that may possibly impact your trailer? On Past RV’s have seen awning seams listed as faulty that were recalled because of faulty seams
(4). Another thought is if you use any aftermarket awning covers during storage that might have weakened/damaged the seam? 
(5). Is there any damage to the aluminum awning roller that aligns with the damaged areas?
Good luck & hope everything works out 🙏🍀