[iOS][Work] Inline math remains blank in a specific message; same message renders correctly on macOS

What issue are you seeing?

In the ChatGPT iOS app's Work conversation view (the header reads “工作”), two inline single-variable math expressions in a particular assistant message are displayed as blank spaces. The same message renders both variables correctly in the macOS app.

The source contains \(x\) at both affected positions. The variable is present in the response text, but is not visible in the iOS screenshots. Other, longer inline expressions and the display equation remain visible in that same message.

The affected reply explains the Riemann hypothesis in Chinese. Two excerpts from the assistant response are:

零点的实部影响修正项随 \(x\) 增长的尺度。

当 \(x\) 足够大时，误差的绝对值不超过某个固定常数乘以 \(\sqrt{x}\ln x\)。

On iOS, the first sentence visually reads “修正项随 [blank] 增长的尺度”, and the second reads “当 [blank] 足够大时”. The square-bracket descriptions here stand for the visible gaps; they are not literal output.

What steps can reproduce the bug?

Observed reproduction in the existing conversation:

1. Open the affected assistant reply in the iOS Work conversation view.
2. Observe the blank inline variables in the two sentences above.
3. View the same reply in the macOS app: both variables are visible.
4. Later, return to the original reply on iOS: both gaps are still visible. A second screenshot confirms the repeated observation.

This establishes repeated observation in the same message, not reproduction after an app restart or in an independently recreated conversation.

Reduced test performed in a new assistant message in the same conversation:

The sentence controls were presented in a numbered list; the original affected sentences were in ordinary paragraphs within a longer reply. This difference has not been isolated as a cause.

The reduced examples did not reproduce the missing-variable problem. There is not yet a standalone minimal reproducer. The dollar-delimiter observation is included only as a control result, not as a claim about supported syntax or a second bug.

What is the expected behavior?

Inline math present in an assistant message should remain visible on iOS and render consistently with the same message on macOS. Mathematical explanations should not silently lose variables.

Additional information

• Affected surface: ChatGPT for iOS, Work conversation view.
• Comparison surface: macOS app, same assistant message.
• Exact app and operating-system versions corresponding to the screenshots were not captured.
• Evidence reviewed: an initial iOS failure screenshot, a macOS screenshot showing the variables, an iOS screenshot of the successful reduced controls, and a later iOS screenshot showing the original message still failing.
• The screenshots were supplied in the reporting conversation and inspected; image attachments are not included in this issue.
• Restart, force-quit, cache clearing, and fresh-conversation reproduction have not been tested.
• This is an observed rendering discrepancy. The internal cause and whether it depends on message structure, layout, or rendering state are unknown.

Related: #22921 (“Support latex math rendering in iOS app”). This report adds the narrower observation that specific inline variables are blank in one message while new-message inline math renders successfully. The issues may share a cause, but that has not been established.

Use the iOS Work conversation view and the affected assistant reply as the reproduction entry point, comparing it with the same reply on macOS. First isolate the message structure or rendering state that causes the two inline (x) expressions to disappear, since the reduced examples do not reproduce it. Done means those variables remain visible on iOS while the existing inline and display math controls still render correctly.