Thanks for following on this thread, Ajain1.

I appreciate you sharing with us a screenshot of your concern. This gives me a better picture of what's happening to the invoices.  Let me help you point in the right direction so you can import the CSV file seamlessly.

When importing invoices, the CSV file should meet the required format. Aside from the Invoice Number, Customer, Invoice Date, Due Date, and Item Amount, make sure it has a Taxable column. Aside from that, the date format should be similar to the sample spreadsheet. There shouldn't be any negative numbers on the template, too.

Now, let's go back to the CSV template and review the mapping of the fields. Make sure the format is similar to the sample spreadsheet.

After reviewing, you can start importing it to QBO. Here's how:

1. Go to the Gear icon at the top to choose Import Data.
2. Tap the Invoices tile to open the Import invoices page.
   
3. From there, click the Browse button to find the CSV file and hit Open to upload it.
   
4. Choose Next to continue.
5. On the Map your column headings page, review the mapping of each field and press Next.
   
6. Follow the on-screen instructions to complete the import process.

For additional resources, check out this link. It provides important tips to follow to successfully import the  CSV file to QBO: Accelerated invoicing with QuickBooks Online Advanced, Part 2: Importing invoices. 

Let me share the Import multiple invoices at once article. It provides detailed information on the do’s and don’ts when importing the sales transactions. From there, you’ll see the complete steps on how to prepare the spreadsheet up to importing the invoices. Go to the Prep your Spreadsheet section and proceed to #3 to see the requirements to transfer entries and to access the downloadable sample template.

Stay in touch if you have any other concerns or questions. I’ll be right here to answer them for you. Have a good one.