EDI810 invoice imported with freight amount is not generating freight distributions

EDI810 invoice imported with freight amount is not generating freight distributions when invoice is validated first time. This results invoice in ‘Needs Revalidation’ status and invoice goes on ‘Distribution Variance’ Hold. However when we validate the same invoice AGAIN without updating anything on the invoice the distribution variance is automatically corrected. Please note here that 'Prorate across all item line' is enabled at freight invoice line and the expectation is Invoice should get validated successfully first time itself prorating freight amount in distribution