This was grown in the subtropical environment of Hong Kong.. why the heck doesn't it turns purple?

Can't help with the ID as I am new to figs but not all figs turn purple when ripe.

It was turning purple, but won't get any darker, before falling to the ground. It's sweet.

I have a fig that looks somewhat like this one. It is a "heritage" fig- one from an old home in the coastal area of North Carolina, and no-one knows the variety. It is a large fig, which develops streaks of purple late in the growing season, which merge together on the end away from the stem. It never becomes all-purple. So--I believe that this characteristic is genetic. Varieties that are known as purple figs--petite negri and purple mission, for example, are all purple. If it is a good fig, that is all that counts!!