Where does the bug appear (feature/product)?
Cursor IDE
Describe the Bug
Environment
- Cursor Version: 1.7.28 (please update with your actual version)
- OS: Linux 6.1.0-39-amd64
- Date: October 3, 2025
Summary
When AI responses contain multiple Mermaid diagrams followed by code blocks, the code blocks display shifted/wrong content in Cursor’s chat markdown renderer. However, when the same chat is exported to a .md file, all content renders correctly in external markdown viewers.
Description
In Cursor’s real-time chat markdown renderer, when a response contains multiple sequential patterns of:
[Mermaid Diagram] → [Code Block] → [Mermaid Diagram] → [Code Block] → ...
The code blocks display incorrect content:
- 1st code block: Shows the 1st mermaid diagram’s source code (should show Python/Bash code)
- 2nd code block: Shows the 1st code block’s content (should show different code)
- 3rd code block: Shows the 2nd mermaid diagram’s source code (should show code)
- Pattern continues with consistent offset
Steps to Reproduce
- Ask AI to generate a response with multiple mermaid diagrams and code blocks
- Use this example content:
## Test 1
```mermaid
graph TD
A["Node A"] --> B["Node B"]
This is test 1 code:
print("Test 1")
x = 1
Test 2
graph TD
X["Node X"] --> Y["Node Y"]
This is test 2 code:
print("Test 2")
y = 2
Test 3 (no mermaid)
print("Test 3")
z = 3
Expected Behavior
- Test 1 code block should display:
print("Test 1") - Test 2 code block should display:
print("Test 2") - Test 3 code block should display:
print("Test 3")
Actual Behavior
- Test 1 code block displays:
graph TD A["Node A"] --> B["Node B"](mermaid source) - Test 2 code block displays:
print("Test 1")(previous code block) - Test 3 code block displays:
graph TD X["Node X"] --> Y["Node Y"](previous mermaid source)
Pattern: Each code block shows the content from 1-2 blocks earlier, creating a systematic offset.
Critical Evidence
The exported markdown file is completely correct!
When exporting the chat conversation to .md file and opening in external markdown renderers (Typora, VS Code, Mark Text, etc.), all content displays correctly without any offset. This proves:
AI-generated markdown source is correct
Cursor’s real-time chat markdown renderer has a content buffering/caching bug- Mermaid diagrams themselves render correctly
- Only the subsequent code blocks show wrong content
Screenshots / Screen Recordings
Operating System
Linux
Current Cursor Version (Menu → About Cursor → Copy)
- Cursor Version: 1.7.28 (please update with your actual version)
- OS: Linux 6.1.0-39-amd64
- Date: October 3, 2025
Does this stop you from using Cursor
Yes - Cursor is unusable