[Bug]: gemini-3.1-flash-image (not preview) not working?

[lazyfai]

Before submitting

• I searched existing issues and did not find a matching report.
• I can reproduce this issue on the latest version of the repository or current main branch.
• I removed or masked secrets, tokens, and private endpoints from my report.

Affected area

pipelines/google

Bug summary

Image genearation works well with gemini-3.1-flash-image-preview but not gemini-3.1-flash-image

Current behavior

Used with Open-WebUI since 0.6.x to now 0.9.5.
We used gemini-3.1-flash-image-preview and recently google released the non-preview version, aka. gemini-3.1-flash-image, but I found that with gemini-3.1-flash-image, the image generation seems done ( I can see token usage ) but no image shown. Switching to gemini-3.1-flash-image-preview works fine with exact same prompt same configuration.

Expected behavior

gemini-3.1-flash-image should works well same as gemini-3.1-flash-image-preview

Steps to reproduce

1. Generate an image with gemini-3.1-flash-image-preview, it should work
2. Open a new chat, change model to gemini-3.1-flash-image
3. Do same prompt for image generation
4. After 10-12 seconds, nothing shown, token count shown, just no image showing

Relevant logs, errors, or screenshots

No error at all

Environment details

Open-WebUI 0.9.5 running with official docker image along with other tools, eg. vectordb, litellm, etc.
Latest function from https://github.com/owndev/Open-WebUI-Functions 1.15.2

Additional context

No response