I have a crude workerbot and a basic workerbot set with the same brain setup
Forever[ Repeat till Hands full[ Find Tree seed, move to seed, pickup seed], Move to Seedling Tray, Repeat till Hand Empty [ Add to Seedling Tray]]
This ends up with the crude bot picking up a full stack and depositing it, but the basic bot will grab one, go deposit it, and get stuck, the red arrow flickering between move to seedling tray, and add to tray, although i dont think thats the full story, as if i add a move order to the beginning ( Forever[ Move to x,y, repeat till hands full[... ) the red arrow will flicker between pickup seed, move to seedling tray, and add to seedling tray, but will never re-execute the move to x,y order