Thanks everyone, so I get it there is smoke fiddling involved I guess. I was thinking of returning to amazon and getting a replacement thinking its a malfunction.
Just to note from my observation, I tried 5ml and it was off by an extra 1 ml or so, so it seems part of the problem is me wanting to dispense 1-2 ml (my tank needs 4-5ml of Ali per day that's all and I wanted to do it in 2-3 increments), it seems to be more accurate with higher volumes. So will keep trying it backwards as you guys mentioned, so will try calibrating to 75 ml or so and trybto play it backwards.
But just wanted to make sure it's not a malfunction, stay tuned will keep you posted and thanks everyone