I agree the cover spring may be getting week.
I had a similar issue and it was not the length. Ever since I now have a heavy duty twisty tye in wrap around the cable and the cover. And the twisty is tethered to the 7 wire cable so I do not loose it. This double wire twisty comes on garden hose hoses. It only last about 8 months and need a new one if you camp a lot. The trick listed about about using solid copper wire is a good thought. I may try that when my stock of twisty ties runs out.
Having this unconnected is not good. This is where a truck that has some level of being able to stop you for your size camper comes in handy. I my case the camper is almost at 10,000# when loaded. I have been fortunate I could engine brake to slow down then stop with the truck. Even if you have a good cover, tying it locked is not a bad idea. I know I will now always tie mine.