The motors are marginal in power, especially for the larger awnings that have a lot of inertia. If the voltage is even a tiny bit low or the mechanism slightly dirty or corroded, the awning may not move at all. Lubricate the pivot points in the struts and check all electrical connections. As little as 0.1v can make a difference here, simply because the motor needs every bit of its capability to do the job.
In an automatic awning, the motor has to overcome the pressure of the struts, which is what forces it out in the first place. To deploy, the motor unwinds the roller a bit and the gas struts push the now-loose arms out. To roll up again, the motor has to turn the roller tube against the strut pressure as well as inertia, so the first few feet take a lot of torque.