Leveling SOul Crystals

I really don't know how it's here.

But i have went with a full party ( everyone has quest enhance your weapon ), to zaken, freya, freya hard, frintezza, quenn shyeed's, etc, several times. And soul crystals never get to pass from lvl 15.

Could you please check that please
it has a chance to get lvl up , in my clan many times i go tezza/zaken/freya/ they all lvl get lvl upped ! )) check all your pt if they have quest also .
well i have done almost every raidboss possible, except valakas antharas and Baium in 2 laptops, so i know every char has quest, but it never seems to get lvl up, i get chances and %, but it's kind of ridiculous, out of 9 chars, and doing the RB every day, no crystal get to 16