I have the same question. It is an old account it probably had a lot inaccuracies from the previous person using the account. We want to start with Jan. 1 2019. What would be the correct process without me doing a workaround. This is an old desktop Quickbooks version. Thanks!
"We want to start with Jan. 1 2019. What would be the correct process without me doing a workaround."
Any prior amounts from income and expense are already rolled into Equity. That means, to get Bank on track, the offset entry for the One Check (if the bank shows too high) or the One Make Deposit (if the bank shows too low) is offset as Equity. Keep this off of the P&L.
You also should address if Loan accounts and credit card and other balance sheet accounts are being properly used and managed and reconciled. This likely is not the only error in this file.