Bug in G/L Entries

i think we have bug ,
It is a very strange changes in system setting happened, how can we have the purchases for 9 months of only QR 183m, while it was 400+ for 6 months, really this strange, I how it happened, The Balance Sheet is totally wrong, Supplier Balance, Purchases, and returns, and for sure this a wrong modification done to setting without a permission.
after that we check the G/L entry for one sample invoice ,should be posted to Purchase , local account , we found it's posted with two lines for the same account " supplier locals" credit and debit in the same time.

all figuers in G/L is wrong , my question if any change in posting group it will effect the old entries.


thanks