GL: Primary, Secondary & Reporting Ledger - Exchange rate used for accounting

We have four ledgers as below

> PL       - INR Currency - 4-4-5 Calendar

> PL RC - USD Currency - 4-4-5 Calendar

> SL       - INR Currency - Apr to Mar Calendar

> SL RC - USD Currency - Apr to Mar Calendar

The default rate type is 'Corporate' and retain transaction rate type is 'No'. However we observe the difference when EUR transaction is performed using 'User' and 'Corporate' exchange rate as highlighted in yellow below. Would like to know the logic in derivation of amount and how we can over come to have the same amount