AP Credit Memo fails Validation with message 'This detail transaction fails funds check' when a line

Hi There, We are having a strange situation, where AP Credit memo fails Validation with message 'This detail transaction fails funds check' And this funds check is happening on the line which is discarded. I do agree from accounting point of view that once the credit memo line/s are discarded the reversal accounting entries for that line are created. hence it is a credit memo the reversal entries for discarded line would be DB liability. CR item Expense. (Account having budget control) Does funds checks done on the account which is on credited side. we also tried validating  by adding