Spell checker incorrectly flags common English words in Codex Desktop 26.616.81150 (Windows 11)

What version of the Codex App are you using (From “About Codex” dialog)?

Codex Desktop 26.616.81150 (Windows 11)

What subscription do you have?

PLUS

What platform is your computer?

• Codex Desktop Version 26.616.81150 (Released June 23, 2026) Windows 11 UI Language: English (United States) localeOverride = "en-US"

What issue are you seeing?

Observed behavior:
The spell checker flags many common English words as misspelled, while accepting other English words and also accepting French words.

What steps can reproduce the bug?

Observed behavior:
The spell checker flags many common English words as misspelled, while accepting other English words and also accepting French words.

Examples:

Flagged:

• write
• written
• writing
• develop
• developed
• development
• developer

Not flagged:

• house
• computer

Also not flagged:

• bonjour
• maison
• ordinateur

Additional observations:

• Windows language switching works correctly (French and English keyboards installed).
• Codex UI language is set to English (United States).
• Right-clicking a flagged word only shows "Learn Spelling".
• No spelling suggestions are displayed.

What is the expected behavior?

Common English words such as "write", "written", "writing", "develop", "development", etc. should not be marked as misspelled.

Additional information

Suggestion: why does not CODEX have a standard Windows 'Check spelling' menu, offering a choice of language when one is typing a prompt in CODEX ?