This is not the impression we want you to experience when using QuickBooks Online (QBO) Simple Start version, @Arthur Götz . 

Please do know that the Transaction Detail by Account report is available in the Essential and version of QuickBooks Online (QBO). This helps you generate a transaction report that shows the description of the transaction. In this case, we can export the report in the Simple Start version to Excel and modify the report you need. Here's how: 

1. Go to Business overview and select Reports. Select the Custom reports tab.
2. Find the custom report on the list.
3. Select Edit from the Action column for the report you want to export.
4. Press Export As PDF or Export As Excel.

In case you might want to memorize reports, you can read this article for your future reference: Memorise Reports. For the split transaction to show the details of it, we can run the Transaction List with Splits report. Here's how: 

1. Go to Reports.
2. Type Transaction List with Splits in the search bar.
3. Change the Report period.
4. Click on Run report. a workaround, you can export the Transaction List with Splits report to Excel so you can separate it from there. You can follow the steps provided by my colleague above.

Also, for the split category, it will show on the report if the transaction has multiple line items when categorizing. To verify, open the transaction to check the categories associated. To know more about it, see this article: Enter a split transaction into the account history.

If you need additional tips while running and managing your reports in QuickBooks Online, you can check out this link: Run reports in QuickBooks Online.

I'm looking forward to hearing from you again. If you have any other QuickBooks questions, please feel free to add a comment below. I'm always here to help. Have a great day!