You may not be aware but super payments are only considered to be paid for the purpose of claiming a tax deduction once they have been received by the super fund, not on the date that the Small Business Superannuation Clearing House (SBSCH) accepts them.
As per the Australian Taxation Office:
To ensure you can claim a deduction for the 2019–20 income year, you need to allow processing time for your super payments to be received by your employees’ super funds before the end of the 2019–20 income year. Payments need to be accepted by the SBSCH by 23 June 2020.Small Business Newsroom, ATO
Don’t forget to check the super fund details with your employees in case you need to update them in your SBSCH account, including a change of ownership of a superannuation product. If a change of ownership has occurred, the super fund’s ABN or Unique Superannuation Identifier (USI) may also have been changed for your employee’s super account. Super funds will communicate any such change to its members (your employees), which your employee should be able to provide to you.