Probably a reflection of my lack of expertise, but I couldn't find the 'journal settings in the invoicing' (at least, nothing I could change that had to do with analytic accounts.  With the need to address this problem, I came up with a different approach, shared below.  I am using Odoo 15 and, depending on how you've configured things, the instructions that follow may not exactly mirror what you see.  I hope that this is of some assistance to others.

1.      Navigate to Sales|Orders|Orders and open the first sales order.  Then, click on the ‘Other Info’ tab and see if there is something recorded in the ‘Analytic Account’ field.  If so, use the right arrow to scroll to the next sales order.  Continue until you find a an empty ‘Analytic Account’ field.

2.      If the Analytic Account field is empty, click on the field’s data entry area to see if it is disabled (nothing can be entered).  If you can enter something in the analytic account field, now would be a good time to do so, save it, and then continue scrolling to the next record and repeat the process.

3.      If the Analytic Account field is disabled, observation tells me that an invoice was created against it. At the top of the screen, click on the Invoice link (but take a screenshot of it first, since you’ll be needing some of that information later).  Proceed to step 4.

4.      “Reset to Draft”…the invoice, and then Cancel it (but, again, make a screenshot or take a picture of it first, since you’ll be needing that information later...if it was only a partial payment against the sales order, make a note of that as well).  It should show as Cancelled in the top-right corner.  Then, press button link at the top that returns you to the Sales Order.  Proceed to step 5.

5.      Once back in the sales order, click on the Cancel button followed by the Set to Quotation button that appears.  The Analytic Account field should now be enabled.  Fill in the Analytic Account manually ‘and then press the tab key’ to exit the field.  This, in my case, pulls up a window asking you to specify the Analytic Plan name…I used the sales order number (S00XXX) for this and then saved it.  Once back in the sales order, save it and then proceed to step 6. (When saving it, Odoo may modify the Analytic Account name).

6.      Confirm to make the quotation a sales order. Proceed to step 7.

7.      Next, ‘Create Invoice’.  This will allow you to create a ‘draft’ invoice (again, in this process you’ll want to use the original Invoice Date and Due Date).  This is important because, otherwise, the invoice number may reflect the current month and year and show up in your fiscal reports in the wrong time period.  Odoo will assign a different invoice number than the original invoice number so you should document what you’ve done in a log note or perhaps in the invoice’s Customer Reference field.  If the invoice was a partial payment against a sales order, make sure you are recording the correct amount.  Save the draft invoice.  If the invoice was already paid for by the customer, proceed to Register Payment (making sure that the Payment Date, on the window that pops up, reflects the month that it was actually paid so that it shows up in the correct financial reports.