macOS Sequoia 15.5 Finder Sync & iCloud Hydration Failures (M4 MBP)

[ProxCause]

Hi everyone,

I'm running **macOS Sequoia 15.5** on a new **M4 MacBook Pro (16")** and encountering persistent Finder sync issues that seem related to iCloud file hydration:

🔍 Issue Summary:
- Finder shows placeholder files, but fails to hydrate them (spinning forever or returns 0 KB)
- Files are confirmed present via `mdfind` and `find`, but won’t open or download
- iCloud Drive folders under `~/Library/Mobile Documents/` behave inconsistently
- `bird` process uses excessive CPU for hours with no resolution
- Reboots, relogins, and toggling iCloud Drive fail to resolve
- Apple Support reviewed logs but had no solution; case remains open

🖥️ Environment:
- macOS 15.5 (24F74)
- Apple Silicon M4 (16” MBP)
- All Apple services authenticated and active
- Same iCloud folders hydrate correctly on other Macs (Intel and M1)

✅ Tried:
- `killall bird` and restart
- iCloud Drive toggling
- Safe Mode boot
- Isolating network, user profile, and disk utility first aid

❓ Anyone else seeing this on Sequoia 15.5?
Would love to know if:
- Other M4 MBP users are seeing similar hydration or sync stalls
🔗 Also cross-posted on Apple Support Community https://discussions.apple.com/thread/258108885.

 

[ProxCause]

Quick update:





✔️ No VPNs installed


✔️ iCloud Drive toggling, Safe Mode, and disk utility didn’t resolve


✔️ File permissions under “Get Info” show expected ownership (me + staff)





I ran a full EtreCheckPro diagnostic — sanitized for privacy. Hardware checks out fine (Apple M4, 36GB RAM, 3.6TB free), but there are repeat stalls and crash logs tied to bird, knowledgeconstructiond, and other sync-related daemons. Background CPU and idle I/O usage spike when Finder hydration stalls.





Let me know if anyone else with a 2024 MBP (M4) on macOS 15.5 sees similar iCloud Drive behavior — or if you’d like me to post the full redacted report.





Thanks again for the insights.