My black glutinous rice is not chewy at all?

Black rice is the only rice I measure rice and water. Rice rinsed once to remove contamination. One cup of rice, two water. Boil on low heat for 50 minutes. Stir from time to time. Leave for 5-10 minutes.
Soaking black rice overnight (or a day) should make the rice act as cooked (so chewy). If it's not I would supect there is something not right with rice itself. Althought it look good to me (but the one I use have a little more gloss but maybe that's just package effect)

Black rice is "hulled", meaning the fibrous outer husk is removed, but not (or only minimally) "polished", meaning the thin but tough bran layer is left on. (It's the bran that provides the color to black rice.) Different varietals of rice, and different processing methods, will lead to a thicker or thinner layer of bran.

It sounds like the rice you have has a relatively thick bran layer, meaning a tough outer layer will remain after cooking. There's nothing you can change about your cooking process to address this.

From the picture, I note a pretty wide variance in color, indicating low-quality processing (the husk was left on a few grains, and the bran partially rubbed off others). If you have a choice of brand, look for black rice with as uniform a color as possible.