# Selling in different UOM not calculating stock QTY correctly

Greetings community,
I hope someone can help with this problem:
we have product A sold in BOX but can also be sold in packets and units. Its price is 65. Each box has 3 packets and each packet has 10 units like this
1 box = 3 packets
1 packet = 10 units

we created the item and setup each UOM and unticked “must be whole number” in UOM settings, and set the conversion rates:
box = 1
packet = 0.3
unit = 0.03

we added stock of 5 boxes and tested the UOM in the POS and it calculated the price correctly
1 box = 65
1 packet = 21.66
1 unit = 2.13

but here is te problem: every UOM is deducted from the stock as one box
for example:
we sold 2 packets, but deducted 2 boxes from the stock and the remaining became 3, it should be 4.33.

we also tried with stock QTY of 0.66 which means there are two packets available, but in the POS it said stock QTY not enough for two packets.

does anyone knows how to correct this? or is it a bug in the POS? any help would be appreciated, and sorry for my bad English.

PS: i will prepare image to further explain my problem.