awning rolling up, arms and supports not aligned

First thing to do is to measure the amount of tube exposed with the awning extended. Both ends should be about the same. If not the awning needs to be pushed/pulled until the measurements are equal. This can easily happen if the awning has been out during high winds.
It happened so often on a previous 5th wheel I owned that I put a small sheet metal screw in each end of the slot to hold the awning in place.