I am experiencing a persistent iCloud Notes synchronization problem on my iMac running macOS Tahoe 26.7.
Problem
New Notes created on my Mac under the iCloud account are not uploaded to iCloud.
Existing iCloud Notes can be downloaded and displayed on the Mac, but new or modified Notes created on the Mac do not appear on iCloud.com, my iPhone, or my iPad.
The Notes app also shows a continuously spinning synchronization indicator next to iCloud.
This problem does **not** occur with my Gmail Notes account. Gmail Notes synchronize correctly.
Reproduction
1. Open Notes on the iMac.
2. Select the iCloud account.
3. Create a new note, for example: `SYNC-TEST-1`.
4. The note appears immediately in the Notes app on the iMac.
5. Wait several minutes.
6. Check Notes on iCloud.com — the new note is not present.
7. Check Notes on my iPhone and iPad — the new note is also not present.
8. The synchronization indicator next to iCloud continues spinning indefinitely.
I also created a completely new iCloud folder called `SYNC-MAP-TEST` and a note called `TEST 123` inside it. Neither the new folder nor the note appeared on iCloud.com.
This shows that the problem is not limited to one particular corrupted note.
Settings verified
* iCloud Notes: ON
* “Sync this Mac”: ON
* “Access iCloud Data on the Web”: ON
* Advanced Data Protection: OFF
* Notes → Accounts → iCloud → Notes: ON
Troubleshooting already performed
* Restarted the iMac.
* Turned “Sync this Mac” OFF and ON again.
* Turned iCloud Notes OFF and ON again under Notes → Accounts.
* Verified that existing iCloud Notes can still be downloaded to the Mac.
* Verified that Gmail Notes synchronize correctly.
* Checked iCloud.com directly.
* Checked the problem on both iPhone and iPad.
* Checked Activity Monitor for relevant iCloud processes.
* The processes `accountsd`, `cloudd` and `bird` are present, but `cloudd` and `bird` remain at 0% CPU while the Notes synchronization indicator continues spinning.
When I turn “Sync this Mac” OFF, the existing iCloud Note disappears from the Mac and the spinning indicator stops. When I turn it ON again, the existing iCloud Note returns, but newly created Notes still do not upload and the spinning indicator starts spinning again.
Important
I have already made a backup copy of my important Notes in Microsoft Word, so I am not concerned about losing the existing Notes.
I have deliberately **not deleted or modified `NotesStore.sqlite`, `NotesStore.sqlite-wal` or related Notes database files**, because I do not want to risk damaging the local Notes database without an Apple-supported procedure.
Question
Could this be a macOS Tahoe 26.7 / iCloud Notes synchronization problem?
In particular, why can the Mac download existing iCloud Notes but cannot upload newly created Notes or folders to iCloud?
I would appreciate an Apple-supported diagnostic or repair procedure, or instructions for collecting the appropriate diagnostic logs so that Apple can investigate the problem.
