puzzle 21 - base built, idols in place, hollow tree trunk standing by, base up, hardened glass made, says a wooden gear is needed, moved all villagers around village twice, nothing comes up. Perfect villager to the craft hut, nothing comes up. Have no clue how to proceed.

puzzle 22- trenches dug, dam built, reservoir built, dam removed and water wheels built, filter crafted and in place, pins made and secured, pipe in place, but the puzzle is not complete and villagers dragged all through reveals nothing. Perfect villager dragged to craft hut reveals nothing. No clue how to proceed. Can someone please give me a hint or a spoiler or something?