Thanks for your reply, @cdodok.
I have another troubleshooting step you can try for the invoice number to display the correct sequencing.
When there's an unexpected result in QuickBooks Desktop, we always recommend updating it to the latest release. Then, run the Verify Data and Rebuild Data Utilities.
These are built-in tools used to validate whether your file is still in good shape and fixes common errors. Before performing the troubleshooting, it’s always a good idea to save a backup of the company file.
This way, you have a copy of the transactions. Once you’re ready, let’s go to the File menu to run the tools.
For an overview of how to resolve common data issues, check out the Fix data damage on your QuickBooks Desktop company file article.
Reach out to me if you have any other concerns. I’m always here to assist further. Have a good one.