All right folks !
Here are the facts
1/ I built a furnace Q100 (with fibers, clay, and water Q100) on a ground Q100 (if there is an influence or somethin else.
2/ I treated 400 iron ore of Q100 = 1ingot of 100 and 19 of 99 (the durability is in cause). After, I treated 400 iron ore of Q50, and i got 20 ingots of Q64.
3/ I made 2 clay anvil forms with Q100 and Q50 materials and I got one of 100 and the other 70.
4/ And I finally crafted 2 anvils
one of 71 and the other of 98.
I can not make better. We have the same problem with leathers. I also don't know why I don't have a better anvil with a form of Q70. I got 1 point more ...
In my opinion, there is definitively a problem with the quality.
Veda