Settle customer payment deductions using the matching invoice New feature
the setting from this feature won't be visible until you have activated visibility for rebate management (in 10.0.39).
Rebate management>Setup> Rebate management parameters>Feature visibility>activate>yes.
Then you will find a new tab in Accounts receivable>setup>accounts receivable parameters>deductions>general>settle customer payment deductions.
If you require the legacy functionality: set the parameter to "match to open payments". Watch out: by default this is set to the new functionality "match to invoice"!
regards,
Allan