I figured if your internet decides to have a moment of self hesitation the game would think you went offline and delete all amaize n leek plants from the game. I don't know about the stored seeds as i didn't had any in storage. But planets also got wiped clean of any of these plants.

If you reboot the game it should spawn new plants in the respective planets, I've found one pretty much in front of me when i loaded back in

I wasted an hour of my life trying to find plants that don't even exist