Dear Tomoya Ono
Thank you for your quick response and we also appreciate you spent your precious time doing the tests and providing the detailed information and screenshot to us.
Per your update, this behavior happens both in Mac and PC. We did tests on our end, but we can't reproduce the same result as yours. In this scenario, to check if this behavior is related to the specific notebook or all notebooks, can you copy all the content to a new created notebook then to check the result?
If this behavior happens in all notebooks in OneNote. to confirm if this behavior is related to your OneNote app on Samsung s7 tablet, may I know if it's convenient to you to sign in your account in another device, such as iPad or OneNote for mobile device to check the outcome?
And can you tell us does other users in your organization also have this behavior?
Welcome to update the latest situation to us. We'll help you all the time.
Really appreciate your patience and understanding.
Sincerely,
Stacey | Microsoft Community Moderator