Outlook 365: Folder sorting resets automatically to A–Z

Outlook 365 – Folder sorting resets automatically

Environment:

- Outlook desktop app (Microsoft 365)
- Exchange / Office 365 mailbox
- Dark mode enabled
- Multiple shared mailboxes

Problem description:

Outlook automatically changes the folder sorting/display settings without user action.
The option “Sort subfolders A to Z” reactivates randomly during the day.
The configured sorting (e.g., Received – Descending) resets several times per day.
In View Settings, the sorting remains configured correctly, but visually Outlook displays a different order.
The issue occurs across multiple folders (Inbox, shared mailboxes).

Actions already taken:

- Verified and modified sorting via View > View Settings > Sort.
- Applied the same view to multiple folders.
- Confirmed that the settings remain saved correctly.
- Issue persists: the parameter stays the same, but Outlook displays mails differently after refresh.

Possible causes considered:

1. Outlook bug – display refresh resets the sorting visually even though settings remain unchanged.
2. Corrupted Outlook views – local view definition might be corrupted (outlook.exe /cleanviews).
3. Outlook add-in – third-party add-in may override sorting.
4. Exchange synchronization – server-side policy may enforce default sorting on shared mailboxes.
5. Recent Microsoft 365 updates – some users have reported similar issues in 2025 (views automatically resetting).

Request:

- Confirm whether this is a known Outlook 365 bug related to automatic resetting of folder views/sorting.
- Provide solution or patch/workaround.
- Official Microsoft recommendations to prevent Outlook from reverting to A → Z sorting automatically.