My opponent had a Dozing Dragon on board that was summoning 3/5 taunts while dormant as per usual, and had woken up from dormant. I then used Eternal Layover as part of a board clear combo with Ghoul’s Night and their Dozing Dragon came back from reborn dormant as a 3/1; I didn’t know that’s how reborn + dormant minions work, but I guess nothing wrong yet.
Then the bug: their 3/1 Dozing Dragon that was back to 2 turns of dormant didn’t summon a 3/5 taunt at the end of their turn.
Unfortunately I don’t have a screenshot as I’m new to reporting bugs. But I can say they also had a Lumia on board when I cast Eternal Layover into Ghoul’s Night, as well as multiple other minions. We both had several cards in hand, with my hand including a Corpscicle that had been returned to hand via spending 3 corpses.
I will also note that I saw a bug on Reddit with Dozing Dragon not summoning more whelps while dormant in a different circumstance, namely a copy of an opponent’s Dozing Dragon being summoned via Matching Outfits.