I can provide additional information on how to disable the auto-fill feature in QuickBooks Desktop.
The previous discussion talks about QuickBooks Online. Since you're using the Desktop version, you can turn off the recall preference by following the steps below on your company file:
Go to the Edit menu at the top.
From the list, select Preferences.
On the Preferences window, hover to the General topic.
Under Automatically Recall Information section, uncheck the Automatically remember account or transaction information box.
Click OK.
This action applies on all future transactions you will create in QuickBooks.
If you have other questions or need further assistance, please know that I am here for you. Update this thread or start a new post in the forum. Have a nice day!