The only bug here is you not reading your quest.

1. Get quest
2. Talk to Rowena in Mor Dhona
3. Talk to Syndony in Mor Dhona
4. Gather crystals
5. Talk to Syndony in Mor Dhona to exchange crystals for Astral/Umbral Nodules
6. Go back to Aradashir with the nodules

You mention having the crystals, you need the two nodules. It's the current objectives of the quest in your quest log.