My tricolor plant is one of my oldest plants. I've harvested other plants that were planted together with it multiple times, and even ones that I planted after the tricolor plant, and the tricolor plant is still stuck at Full Grown Plant stage (not withered) without going to the next stage. Is this a bug or am I doing something wrong?

Decided to edit to add this: the wiki says it's 350 hours at the ripe product stage. Is that 350 hours total or 350 hours from the previous stage to the next?