Do you need to file an issue?

• I have searched the existing issues and this bug is not already filed.
• I believe this is a legitimate bug, not just a question or feature request.

Describe the bug

gpt-5.x models fail under latest release. Using gpt-4o-mini or other models works fine.

Steps to reproduce

Steps to reproduce:
Set LLM_BINDING = openai
Set LLM_MODEL = gpt-5.5
Launch official docker container for v1.3.5
Try chatting, or generating a quiz. Nothing will come back.

Expected Behavior

Should get a response.

Related Module

Dashboard

Configuration Used

Use docker-compose.yaml example from the repo, unchanged.

Logs and screenshots

No response

Additional Information

• DeepTutor Version: 1.3.5
• Official Docker Pre-built GHCR Image

The observed behavior looks similar to #54 but I don't know if the underlying cause is the same.