when entering the opening balances for suppliers and trying to enter a new purchase invoice the amount of the purchase invoice deducted the amount from the opening balances how come and the opening balance is credit
please read and understand the below guide regarding supplier opening balances
https://guides.manager.io/7227
you should be entering starting balance only if you have previously paid the supplier in excess and they owe you money.
if you owe the supplier any money for previous purchases, these purchase invoices should be entered in Manager and starting balance should not be set.
In the Guides section search for Starting balances.