What commonly happens is the vent lid adheres to the roof due to time, temperature, and debris chemistry. Then when the drive system again tries to open it, the resistance is too great and either the arm bends or the drive gear sprocket strips... or both.
The company used to supply free repair kits with good instructions and preventive Aero 303 protectant. Since the company was sold, I hear it’s no longer free. Regardless, after gear/arm replacement, Aero 303 should be regularly used between lid and frame. In my experience that’s not a fail safe, although I respect Aero 303 as a lube-protectant in general.
More of a resolution is seeing to it that the lids aren’t ever tightly cranked down, especially when storing the coach. Let the lid close via motor, then pull the knob and manually turn it just enough to overcome a squeezed shut seal. Then push the knob back up, ready to go via motor next time. Also use caution for example if camping in extra-cold environs where the lid might be iced shut overnight; opening it in the morning by motor or manually to vent cooking fumes, etc., could break things again.
Just be aware if you hear the unit straining, shut off the switch and resolve whatever is restricting the gearing and arm before it breaks.
Joel