[macOS][26.820.60940] Global UI text became noticeably thinner and blurry after update

App version

ChatGPT desktop app (unified Chat / Work / Codex): 26.820.60940 (build 7119)

Platform

• macOS 26.6.2 (25G83)
• Apple Silicon (arm64)
• UI language: Simplified Chinese
• Appearance: light theme

What issue are you seeing?

Immediately after updating to 26.820.60940 (7119), text across the entire ChatGPT desktop interface became noticeably thinner, lighter, and less sharp than it was immediately before the update.

This is visible in all major UI regions:

• left sidebar navigation labels;
• project and thread names;
• main conversation text;
• composer/input text;
• right-side inspector and source panels.

The font size, spacing, and layout are approximately unchanged. The visible regression is primarily in stroke weight, foreground density/contrast, and edge sharpness. Both Chinese and English text are affected.

This is not the same as the older "text size resets between chats" issue. The glyphs are not merely smaller: at the same apparent size, the current build renders them with thinner strokes and a gray/washed-out appearance.

Settings checked

• UI font: System default
• UI font size: 14 px
• Font smoothing: enabled
• The font-weight selector in Appearance is disabled/unavailable
• Adjusting theme contrast cannot restore the previous stroke weight or sharpness

The available Appearance settings therefore do not provide a way to restore the previous rendering.

Steps to reproduce

1. Use the previous ChatGPT/Codex desktop build on macOS in light mode.
2. Observe the sidebar and conversation text.
3. Update to ChatGPT desktop 26.820.60940 (7119).
4. Reopen the same workspace/thread.
5. Compare identical or similar sidebar labels and conversation text.

Expected behavior

Updating the desktop app should preserve readable, consistent macOS text rendering, or provide a supported font-weight control if the default typography changes.

Actual behavior

The current build renders global UI text visibly thinner and blurrier, with lower perceived contrast, making long conversations and sidebar items harder to read.

Additional information

A direct before/after comparison shows the difference clearly. The original screenshots contain private project and thread names, so they are not included publicly here. A redacted comparison can be provided if needed.

Possibly related:

• https://github.com/openai/codex/issues/21511
• https://github.com/openai/codex/issues/22801

Reproduce the before-and-after rendering difference on macOS 26.6.2 with Apple Silicon using builds 26.820.60940 and the previous desktop build, focusing on the listed UI regions and both Chinese and English text. Review related issues 21511 and 22801 for context; done means restoring comparable stroke weight and sharpness or providing a supported font-weight control.