I played Drum Circle with Disciple of Eonar’s “the next choose one card you play has both combined” active, and nothing happened. The card did not play at all, but seven mana crystals were used, and the card was no longer in my hand. No Counterspell secret or similar spell counter active, etc. Felt like a bug.
On a personal note- it left my board empty and cost me the match while on a good run! 