Codex Desktop on macOS loses message hover after long session; main/renderer/GPU stay hot until app restart

What version of the Codex App are you using?

26.513.31313 (bundle build 2867)

What subscription do you have?

Not relevant to repro.

What platform is your computer?

• macOS 26.4.1 (25E253)
• Apple Silicon (arm64)

What issue are you seeing?

After Codex Desktop stays open for a long time, hover interactions inside the Codex UI stop updating correctly.

The clearest visible symptom is on conversation messages: moving the mouse over a message no longer shows the timestamp/hover affordances that normally appear below the message.

Important isolation:

• Finder is normal.
• System Settings is normal.
• Google Chrome is normal.
• Restarting Codex immediately restores the missing hover behavior.

This does not look like a system-wide mouse/trackpad failure. It looks like the long-running Codex Desktop instance enters a bad UI/event-loop/render state.

What steps can reproduce the bug?

1. Launch Codex Desktop on macOS.
2. Keep the app open for a long session (several hours in normal use).
3. Return to an existing conversation.
4. Move the pointer over chat messages.
5. Observe that the usual hover UI (for example message timestamp under a hovered message) no longer appears.

I cannot yet reduce this to a short deterministic repro; so far it appears to require a longer-running app session.

What is the expected behavior?

Hover UI in the conversation view should continue to work normally regardless of how long the app has been open.

What happened locally when the issue was active?

I intentionally kept the bad state alive and captured process, memory, and sample data before restarting the app.

At 2026-05-21 17:01:00 +0800, the affected Codex instance had been running for about 6h39m, and these processes were still consuming high CPU:

PID    %CPU   %MEM   RSS       ELAPSED   COMMAND
435    47.4   0.4    129584K   2d7h      WindowServer
88823  102.3  4.7    1577856K  6h39m     Codex
88830  19.5   0.3    107584K   6h39m     Codex Helper --type=gpu-process
88878  25.6   2.4    793344K   6h39m     Codex Helper (Renderer)
88879   9.0   1.5    490256K   6h39m     codex app-server --analytics-default-enabled

Earlier in the same bad state, top showed:

• Codex physical footprint about 2.1G
• Codex physical footprint peak about 4.3G
• WindowServer about 1.5G

Why this seems app-specific rather than a macOS-wide memory issue

• memory_pressure at capture time reported System-wide memory free percentage: 77%
• There was still around 4GB unused physical memory
• Finder, System Settings, and Chrome were all normal while Codex was broken
• Restarting Codex restored hover immediately

So this does not look like a global macOS memory exhaustion issue.

Local logs / clues

Codex logs for this app run are under:

• ~/Library/Logs/com.openai.codex/2026/05/21/codex-desktop-a112f917-8f05-409b-9f31-acdc6b5fb5a9-88823-t0-i1-022127-0.log
• ~/Library/Logs/com.openai.codex/2026/05/21/codex-desktop-a112f917-8f05-409b-9f31-acdc6b5fb5a9-88823-t1-i1-022131-0.log

One renderer-side error present while the issue was active:

[desktop-notifications][global-error] ResizeObserver loop completed with undelivered notifications.

There were also repeated slow operations in the same log window, for example:

method=mcpServerStatus/list ... durationMs=16363
method=thread/rollback ... durationMs=12429
method=thread/list ... durationMs=9898

Sample data

I captured sample output for:

• Codex main process
• Codex renderer
• Codex GPU helper

The samples show the main thread spending most of its time inside Electron Framework / V8 / Node work rather than idling in a normal event loop. The renderer and GPU helper were also active at the same time.

Representative patterns from the samples:

• main process heavily inside Electron Framework, v8, node, uv_run
• renderer also active inside Electron Framework / v8
• GPU helper active with QuartzCore / Metal / AGX work visible in stack samples

This makes the issue look closer to a long-session Electron/renderer/compositor/event-loop problem than a simple hover CSS bug.

Additional context

Earlier, I checked whether this was a broader system hover failure:

• Finder: normal
• System Settings: normal
• Chrome: normal

Only Codex was broken at the time this evidence was captured.

Related issues

This feels adjacent to:

• #23026 (macOS long session keeps GPU process and WindowServer at high CPU)
• #20643 (hover-related UI affordance missing in desktop app)

But this report is specifically about:

• long-running Codex Desktop session on macOS
• hover affordances in conversation view stop appearing
• Codex main/renderer/GPU/app-server all remain active at elevated CPU
• restarting Codex immediately fixes the problem