Hi @Nathalie Madec
Thanks for reaching out to the Microsoft Q&A forum.
I did not experience this issue in my environment while using Classic Outlook Version 2601 Build 16.0.19628.20214.
To understand your situation more clearly, may I clarify the following details?
1/ Which Classic Outlook version and build are you currently using?
You can confirm this by navigating to File > Office Account > About Outlook.
2/ When did this issue begin?
If you can recall any recent changes or adjustments on the device or in Outlook that might relate to this behavior, it would be helpful.
In addition to the steps shared through the Q&A Assist, you may also try the following methods to see whether they improve the situation:
- Reset the Outlook navigation pane: Press
Windows + R, then enter:outlook.exe /resetnavpane - Create a new Windows profile: This allows you to check if the issue appears in a clean environment. For step-by-step instructions, please refer to the guide here: Manage User Accounts in Windows - Microsoft Support
I hope this information is helpful. If you have any updates or notice any changes after trying the steps, please feel free to share them with me.
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