OWC Express 1M2 Enclosure Experiencing I/O Error 6 During Backups (Not a SoftRAID Issue)

TL;DR: Brand new OWC Express 1M2 enclosure with OWC Aura Pro IV 2TB is force-ejecting during backup operations with I/O error 6. Drive passes all SMART tests. Issue occurs both direct-connected and through OWC Thunderbolt 5 Dock. Posting here since OWC has no forum and others may encounter this.

Setup:

• MacBook Pro Mac16,7 (M4 Pro) running macOS 15.0.1 Sequoia (Build 24A348)
• Drive: OWC Aura Pro IV 2TB NVMe
• Enclosure: OWC Express 1M2 80Gb/s
• Also tested through: OWC Thunderbolt 5 Dock
• Purchased: September 11, 2025 (less than 30 days old)
• Backup software: Carbon Copy Cloner

During CCC backup operations (approximately 90 minutes in), the enclosure force-ejects with system error. macOS kernel logs show:
2025-10-06 23:52:01 kernel: (apfs) apfs_vfsop_unmount:3416: disk5s1 failed to finish all transactions before unmount! (err 6)
2025-10-06 23:52:02 kernel: (apfs) tx_unmount:1878: disk5 tx_finish() failed, 6

The kernel forcibly unmounted the drive due to I/O communication failure - the enclosure stopped responding to I/O requests.

SoftRAID Status:

This is NOT a SoftRAID issue. SoftRAID Monitor consistently reports:
✅ All SMART tests pass
✅ No disk failures detected
✅ Drive hardware is healthy

Most recent SMART test: Oct 6, 22:42 PM - just before the failure at 23:52 PM
Post-failure SMART test: Oct 7, 09:54 AM - still passing
The NVMe drive itself is fine; the enclosure's USB-C bridge chip or electronics appear to be failing under load.

Troubleshooting Done:
✅ Tested direct connection to MacBook Pro - failure occurs
✅ Tested through OWC Thunderbolt 5 Dock - failure occurs
✅ Multiple USB-C ports tested - failure consistent
✅ SMART diagnostics - all pass
✅ Different cables tested - no change
✅ Verified with system logs - clear I/O error 6

Technical Details:

USB Device Info (from System Information):Express 1M2 80G
Manufacturer: Other World Computing
USB Vendor ID: 0x1e91
USB Product ID: 0xde8a
Link Speed: 12 Mb/s

Error indicates:
The USB-C controller/bridge chip in the enclosure loses communication with macOS during sustained write operations. This is a hardware defect in the enclosure, not the NVMe drive.

Why I'm Posting Here:
OWC has no user forum for community troubleshooting
Others may encounter this with the new Express 1M2 enclosures
Documentation for warranty claim
Community might have insights or firmware updates I'm unaware of

Next Steps:
Contacting OWC support for warranty replacement. Will update this thread with their response and resolution.

Questions for the Community:
Has anyone else experienced I/O errors with OWC Express 1M2 enclosures?
Are there known firmware updates for this enclosure?
Any thermal management issues reported with these enclosures during extended writes?

Note to SoftRAID Users:
If you're using OWC Express 1M2 enclosures for backup operations, be aware this hardware issue exists. SoftRAID will correctly report the drive as healthy (because it is), but the enclosure may still fail during operations. This is an enclosure electronics issue, not detectable via SMART monitoring.

Helpful for others experiencing similar issues:
Check kernel logs: log show --predicate 'eventMessage contains "disk5"' --info --last 24h
Look for "failed to finish all transactions" errors
Verify SMART status with SoftRAID
Test multiple connection methods to isolate the issue