I've encountered a bug where the corpse of the Weakened Mind Flayer you can find on the Ravaged Beach disappears as soon as i cross some invisible line on the way to the Emerald Grove.
It doesn't matter if the corpse is currently in the overworld, in a characters inventory or even inside of the Traveler's Chest, it just poofs out of existence.

I have been able to reproduce this bug, even on a completely new save file.
I even nailed down an exact spot where one further step triggers the bug, as shown here (skip to 1:22):



Would someone take the time to confirm if this is reproduceable for anyone?