Celestial Reunion's behold function only sees Changeling creatures as certain creature types (at least while in hand) on Arena matches, not letting you activate it with other creature types.

Example: I have an Elemental Sorcerer (example Soulbright Seeker) in play and a changeling (example Chomping Changeling) creature in hand.

I cast Celestial Reunion and intend to do the additional Behold of two creatures of a chosen so what I pick can go directly into the battlefield.

If I choose the creature type Elemental, Arena will let me behold both the in-hand changeling and the in-play
Elemental.

If I chose creature type Sorcerer, despite both of those creatures also being Sorcerers, it will state the additional casting cost cannot be met and refuse to let me cast it with the additional cost.

I have a deck with this mixed creature set up and would like this bug fixed. Thanks