When I run a report by account and select add "class" column, the column shows up but there is no data even though the transaction indeed has a class when you expand it.

I can provide some insights on how to run a report by class, vara_andrea-yaho.

You use classes in QuickBooks to track sales, costs, or profitability by segment. If you need to run a report by class, there's a specific report to get the data you need. Check out this link to know which statement to generate: Run reports by class.

On the other hand, what you see on the report depends on how you tag a class to a transaction. You can either assign it to each row of the line item or to the entire sales form.

See  these screenshots as your visual guide.

You can also refer to this link to learn the concept when your build a transaction: Targets vs. Sources overview.

I'm adding this link to help track your transactions: Track your transactions by class.

Let me know if there's anything else you need about running a report. I'll be right here to provide the information you need.