I can help you figure this out, Kirsten.
When building reports in QBDT, the system looks at individual transaction lines. If a line matches the report set, then it's added to the report. Please be reminded that different reports read transactions differently. You may think two reports should have the same amount when in fact, show different amounts.
Also, QBDT uses a concept called Source and Targets to apply accounting principles and processes, like recording transactions and displaying reports. Please check understand reports which provide different reports and instructions that the program uses to display data from your company file.
You can create a Check Detail report to show the Bill Payment- Check. Here's how:
- From the Reports menu, select Banking.
- Choose Check Detail.
- Click on Customize Report and select the Filters tab.
> Account = All Accounts
> Amount = Any
> Transaction Type = Bill Payments
> Detail Level = Summary Only
- Once done, select OK.
I've added screenshot for your visual reference:

Also, check this article for more information, Use Check or Deposit Detail Reports to show transaction links and mimic Cash Receipt Report.
Please get back to me if you have any additional concerns regarding reports. I'm always here to help.