Getting INCONSISTENT_RATE on on doing Refund process- R12.1.3

Getting error on INCONSISTENT RATE on doing Refund from AR Receipt

BUT on checking Fnd_LOG, It is found that actual error is coming while interfacing to AP module

äs " (Insert Rejections 1) Insert into AP_INTERFACE_REJECTIONS, REJECT CODE:INCONSISTENT RATE"

Its due to exchange rate decimal value more than 35 . so using workaround of choosing user type rate with limited exchange rate can solve the issue but not possible manually for each receipt in error.

Oracle suggesting a patch which is not working in few testing instance and making process slow.

Please suggest, if any AP setup where we can alter to accept the exchange rate more than 35 decimal value.