Summary
Locked Computer Use intermittently cannot unlock macOS after a display-sleep lock, although automatic unlocking works when the session was locked directly.
The lock-screen guardian checks the accessibility tree and exits with didUnlock=false immediately before loginwindow exposes the password field.
Environment
- ChatGPT desktop app: 26.730.61639 (6234)
- Computer Use service: 26.803.1000621 (1000621)
- macOS: 27.0 (26A5388g)
- Architecture: arm64
- Hardware: Mac mini
- Computer Use service remained running throughout the incident
Steps to reproduce
- Enable Locked Computer Use.
- Leave macOS awake while allowing the display to sleep naturally.
- Let loginwindow create a display-dim lock.
- Start a Computer Use request remotely.
- Computer Use wakes the logical display but reports that automatic unlock failed and asks for a manual unlock.
Expected behavior
After waking the display, Locked Computer Use should wait for loginwindow to finish presenting the password field and then perform its normal authorized unlock flow.
Actual behavior
The guardian finishes before the password field becomes available. It does not submit Return and the authorization plugin is never invoked.
A fresh observed sequence was:
- 14:36:11.313 — display wake begins
- 14:36:11.320 — guardian begins accessibility/UI collection
- 14:36:11.349 — guardian exits normally with
didUnlock=false
- 14:36:11.369 — loginwindow exposes the usable password field
The password field appeared approximately 20 ms after the guardian exited.
The same behavior occurred on multiple attempts. There was no credential rejection: no key submission occurred and the SecurityAgent authorization mechanism was not invoked.
Lock-state difference
Successful automatic unlocks woke from:
kLWLockFromDirectLock (8)
Failures woke from:
kLWLockFromDisplayDim (5)
This explains why Locked Computer Use worked earlier while the physical monitor was off, but later stopped working after natural display sleep created a different loginwindow transition.
Additional diagnostic evidence
The bundled SystemLockScreenController is constructed with:
- Overall timeout: 10 seconds
- Poll interval: 250 ms
- Submit delay: 500 ms
- Verification delay: 2 seconds
The lock monitor has 1.5-second settle and 3-second fallback delays.
However, the failing path exits after roughly 29 ms, so it appears to return before those retry/settle timings are applied.
Suggested fix
When macOS is locked but UserPasswordTextField is temporarily absent, treat that state as transitional rather than as a completed unlock failure:
- Wait up to 1–2 seconds for the password field.
- Poll every 50–100 ms or observe the appropriate accessibility notification.
- Continue with the authorized unlock after the field appears.
- Do not count an attempt until a key submission/authentication attempt actually occurs.
The observed case would have succeeded with even one short retry because the field appeared only 20 ms after the guardian exited.
Summary
Locked Computer Use intermittently cannot unlock macOS after a display-sleep lock, although automatic unlocking works when the session was locked directly.
The lock-screen guardian checks the accessibility tree and exits with
didUnlock=falseimmediately before loginwindow exposes the password field.Environment
Steps to reproduce
Expected behavior
After waking the display, Locked Computer Use should wait for loginwindow to finish presenting the password field and then perform its normal authorized unlock flow.
Actual behavior
The guardian finishes before the password field becomes available. It does not submit Return and the authorization plugin is never invoked.
A fresh observed sequence was:
didUnlock=falseThe password field appeared approximately 20 ms after the guardian exited.
The same behavior occurred on multiple attempts. There was no credential rejection: no key submission occurred and the SecurityAgent authorization mechanism was not invoked.
Lock-state difference
Successful automatic unlocks woke from:
kLWLockFromDirectLock (8)Failures woke from:
kLWLockFromDisplayDim (5)This explains why Locked Computer Use worked earlier while the physical monitor was off, but later stopped working after natural display sleep created a different loginwindow transition.
Additional diagnostic evidence
The bundled
SystemLockScreenControlleris constructed with:The lock monitor has 1.5-second settle and 3-second fallback delays.
However, the failing path exits after roughly 29 ms, so it appears to return before those retry/settle timings are applied.
Suggested fix
When macOS is locked but
UserPasswordTextFieldis temporarily absent, treat that state as transitional rather than as a completed unlock failure:The observed case would have succeeded with even one short retry because the field appeared only 20 ms after the guardian exited.