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.
Tap the File menu at the top and select Utilities to choose Rebuild Data.
These actions will open another screen where you’ll be prompted to close all open windows.
Hit OK to confirm.
In the QuickBooks Desktop Information window, press OK to continue and follow the instructions to create a backup.
QuickBooks will start repairing the file. Please know the process may take some time.
Press OK once it’s done.
Go to the File menu at the top and select Utilities to choose Verify Data.
The tool will start to check your data for any issues.
If QuickBooks doesn't find any problems, select OK.
Choose Rebuild Now if the desktop program finds an issue with your company file.