I'm having the exact same issue with QuickBooks Pro 2021. I was always able to edit the default email template before I clicked on send, and it would save the changes. Now it saves nothing. I have to go to my Outlook outbox, reopen the email and make the changes there, which is quite time-consuming. I never had this problem before, so it must be a recent update. I'm running the most recent update. I also did the rebuild and verify procedures, and there was no problem found in my data.
