The Faerie Dragon button is bugged, unable to be clicked at the Altar. The Dryad and Keeper of the Grove buttons work without issue. This also prevents completing the achievement By Nature’s Call.
Issue appears common since 2021/11/20 (Patch 9.1.5) via Wowhead comments for the achievement.
The issue was repeatable on multiple attempts, for multiple party members, and after reloading UI.