Azaqui The issue is I cannot set the guiding rate as you suggested as ASIAIR implementation does not support it :/
Can you change it with your Hand Controller? With my mount, I can change the guide rate from either ASIAIR or from the Hand Controller; both works.
As I mentioned I tried different calibration times of up to 4000ms.
Try it again. This time, note down the "dist" after 60 steps (I know, it takes a long time to do; but you really don't have much of a choice, except to use Stellarmate, INIGO Sky, or even AstroBerry, if you want something simple minded as ASIAIR).
If 2000ms gives you dist of 11, and 4000ms gives you dist of 22, then 8000ms might be enough.
Remember, you using a guide scope with just 120mm focal length. Most of us are using guide scopes between 200mm and 800mm focal lengths (or even with OAG at 2000mm focal length). And on top of that, who knows what the guide rate is (check the hand controller, just in case).
Chen