Entering PVP duel with spectre permanently destroys it

1. Raise a spectre, including a 1 div perfect guardian turtle that you loved deeply
2. Enter a PVP duel
3. The spectre poofs, no corpse is put in your hideout. I don't even mean my opponent killed the spectre, I mean it just goes away.

I've lost several spectres this way. Good thing they were cheap ones but it's still awful.

i fell victim to this like 5minutes ago... tragic love story.