Launch GL with very wrong value

A Sales Invoice has been posted, “Update Inventory” checked.
Notice how it looked in the ledger:

Note that the value was very high and has no relation to the purchase prices practiced.
Note also that the value was reversed, it came out as a credit and would be a debit.

Here’s a correct release for comparison:

Account Translation:
Custo dos Produtos Vendidos - LG = Cost of Goods Sold - LG
Devedores - LG = Debtors - LG
Estoque em Mãos - LG = Stock In Hand - LG
Vendas - LG = Sales - LG

Has anyone experienced this and can explain the possible reason for this happening?
Detail: This happened only once in all our time using erpnext.