Don’t Delete the deposit. Think of it as an envelope. You can fix the contents.

Yes, Process a Receive Payment for the client as should have been done and make sure it flows to Undeposited Funds.

Then, Open that existing deposit on your screen and use the Payments Icon at the top, […]

Resolution for 'already been reconciled issue: 'How do I replace a deposit transaction that has already been reconciled with a payment from a client ?' available: Yes.

The already been reconciled issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the already been reconciled issue yourself by looking for a resolution described in the article. If it is a complex already been reconciled issue or you are unable to solve the issue, you may contact us by clicking here or by using other already been reconciled support options.

For more information about resolving issues related to already been reconciled in Quickbooks/QBO or to get support for the issue 'How do I replace a deposit transaction that has already been reconciled with a payment from a client ?', click the link below: