I fell into a crystal room at the same instant the ***** **** smashed me, so while the camera went down to the underworld my TumbleSeed was nowhere to be seen. When I pressed A i saw the bottom of the seed switch screen, as if the seed was somewhere above what was visible. I couldn't move the vine at all. Kind of a weird one.
Found another bug with this. Itch doesn't seem to have spoiler tags so: click here