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The possible reasons you don’t see the Item details and Category details on the checks are; you might have missed expanding the fields, and the items table on expenses and purchase forms option is turned off.
Let’s get your Item details to show up on the Create Check screen.
Turn on Item Details:
1. Go to the Gear icon.
2. Select Account and Settings.
3. Click Expense.
4. Choose Bill and Expense.
5. Turn on the Items table on expense and purchase forms.
6. Click Save.
7. Click Done.
There are also instances where the details are minimized, which is why they don’t appear. You can display them by simply clicking the drop-down arrow. You can take a look at the screenshots below:
If you need anything else don't hesitate to post again. I'm always here to help!