I have been fortunate to not have that happen to me, however I have seen it on others campers many times.
Your awning looks like it has the center rafter which ours does too so your awning I'm assuming is in the 20 to 21 ft long range as they really need the center rafter on that length. Regardless of size, during a heavy rain the manual awnings need to be pitched to allow enough water to run off and not pool in the center. "enough" being the key word that is hard to define so you generally go overkill on the run off angle. And high wind is as bad with mega buffeting up and down.
Due to my outdoor kitchen setup under the awning, I have a lot of things stored under the awning over night. Every night before I turn in I lower the one end bottom arm all the way down for maximum water run off, the other end comes down a few holes worth enough that I can still get in the door. The awning tube is tied down on both ends and I have 4 deflappers on the fabric to the top side arms.
The bigger the awning, the faster the problems can happen but they all are affected. Our prior camper had a 16 or 18 ft awning and while it had no center rafter setup, the water and wind issues were just as important to guard against.
If we leave the campsite during the day, both side arms are lowered to the bottom and the ratchet straps on the tube ends are tightened. A wind blast can come up at any time so we always try and prepare for it.
Hope this helps
John