Welcome to the QuickBooks Community again, LekkerByDieSee. Please know that QuickBooks Desktop is constantly changing and evolving based largely on the requests of users. With that, I'll ensure you can send feedback so the feature you want in QBDT is forwarded to the Product Development Team.

I suggest going to the Help icon in QuickBooks Desktop. From there, you're able to choose Send Feedback Online to submit a request about turning off the auto-fill check numbering feature in QBDT. Any recommendations are sent to our engineers for consideration in future updates.

Lastly, you may refer to this article to see steps on how to record a bounced check transaction in QuickBooks by creating a journal entry and a bill payment check: Manage a bounced check you wrote.

Don't hesitate to add a comment below if you need more help managing different features in QBDT. I'm always around to help, LekkerByDieSee. Have a great day!