箭头画不出了

* **L7 Version**:
* **Platform**:
* **Mini Showcase(like screenshots)**:
* **CodePen Link**:

The report only says that arrows cannot be drawn and provides no version, platform, screenshot, CodePen reproduction, file, test, or entry point. First obtain a minimal reproduction and the affected configuration before locating the arrow-rendering path; done would require reproducing the failure and confirming that arrows render correctly without regressions.

Written by the indexing model from the issue text.