Hi @I'm on the pc- hotmail.com ,
According to my research, when you complete a recurring task that has any text in the body, Outlook creates a new occurrence of the task and inserts a row of hyphens at the top of the body text. This is a design choice by Microsoft to indicate the separation between different occurrences of the task.
Unfortunately, there’s no built-in option in Outlook to prevent this behavior.
Some user has already submitted this feedback in a dedicated portal, and you can vote for it:
https://feedbackportal.microsoft.com/feedback/idea/437f5641-b921-ee11-a81c-002248510ddf
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
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