Hi there Ica10,
Thanks for reaching out about your invoice template. QuickBooks Online is a great tool able to assist with creating and sending invoices to customers so they know the amount owed for your services. I can provide some assistance with invoice templates.
If you've made changes to a template, and it doesn't appear on an invoice you've created, when on that invoice's creation page, you can click on the Customize button, located in the bottom bar, and select the template you modified. This will make sure that the template you've updated will be used for this invoice.
If the template is still showing up the same for the invoice when viewing it after selecting the template edited, then the saving when modifying the template might be the error. One possible cause for this not to save would be browsing data. These temporary files can accumulate in the system and cause errors like the one you're seeing. You can resolve errors by following these steps:
If you have any other questions or need further assistance, feel free to reach out here.