If this is similar to Somfy, then Homey does not see if the screens are manipulated by the remote. If that is the case then it can happen that Homey thinks screens are already open and ignore the commands.
Assuming Asun has a middle (stop) button and you did not assign a middle position to that button: What I do is have Homey issue the stop command about 40 seconds after the up or down command (more than it takes to move the screen). That way Homey will always send up or down when I want it to.
