The Stone to emerald trade is broken on Windows 10 Edition.

What i expected to happen:
once i saw that i could trade regular stone for emeralds and unlocked it I expected to be able to do so.

What Actually Happened:

I cooked up some stone from Cobblestone and tried to trade the stone with the second level stone mason that had the stone trade unlocked and found that i could not do so.

Steps to recreate:

1 find a stone mason and level him up till his level 2 trade becomes available. Make sure that they have the stone trade as their first trade on tier 2.

2 cook some cobblestone into regular stone.

3 try to trade the regular stone to the stone mason for emeralds. You will find that when you put the stone into the slot it will say "trader doesn't want this"

I will add screenshots to show what i have found.