Bathroom roof vent cannot be opened in Winnebago Vista

We own a 2014 Winnebago Vista 31KE purchased from Lazy Days in Seffner, FL.We have repeatedly taken our RV back to Lazy Days(140 mile round trip each time) because the bathroom vent sticks and cannot be opened. Every time they tell me it is fixed, and every time when we get back hone it starts sticking again.

To me, it seems like the entire vent is defective and should be replaced. Has anyone else experienced this ?

Thanks.