Using New Outlook on Windows for professional communication and productivity
Same thing happens to me. However, I discovered that the emails remain in drafts only if I do something (delete, archive, move) the original email to which I am replying prior to the email send buffer time. If you allow the email to get through the buffer time before taking an action on the original email, (5 to 10 seconds if you have moved the settings to wait 5 or 10 seconds before sending an email), it will send.