Prior Year Adjustment Changed Beginning Balance on Account

Why did a journal in period 13 adjust the beginning balance on account?

Account Inquiry

Account Master

The Closing balances setting in Account Master is set to Carry

Financials > General Ledger Menu > Set Up/Chart Of Accounts > Account Master

1. Click Search

2. Enter [Org and Object codes] or [segments] if using long account

3. Accept

If the Closing balances is set to Carry in Account Master the account will carry forward the actual balance from prior year