The transaction detail by Tax code from the Taxes Tab and Standard Reports are the same, Shiela. Let's review the filters that were applied when sorting transactions to ensure that everything is accurate. 

Also, let's consider checking the accounting method that is set to Accrual basis, as this affects how transactions are recorded in your financial reports. 

I've added a screenshot for your reference.

Moreover, if you require assistance with customising reports in QBO classic and modern view, here are some articles you can refer for future guidance:

• Customise reports in QuickBooks Online
• Customise reports in QuickBooks Online using modern view

I've added this article to learn more about tax codes:

• How do I set up sales GSR rates and use them on forms?
• GST/Tax Exception Detail Report

I'm all ears if you have other concerns about running reports in QBO. Just click the Reply button to add your comment so I can assist you further.