If you want to create manual invoices for projects that are added to a recurring invoice, you need to go to Preferences/Invoices and Estimates and enable “Allow generate manual invoice for project included to recurring profile”:
If active, you can create now for projects that are added to a recurring invoice manual invoices. In the following two screenshots you will see the difference whether you enable this feature or not.
If not active, you can only click “show recurring invoice” – it is not possible to create a manual invoice for that projects:
If active, you can generate an invoice as if there isn’t any recurring invoice: