Computer Use not enabled for gemini-3.1-pro-preview (was working on gemini-3-pro-preview)

Gemini API
1

The Gemini 3 developer guide states:

Gemini 3 Pro and Gemini 3 Flash support Computer Use. Unlike the 2.5 series, you don’t need to use a separate model to access the Computer Use tool.

Computer use worked with gemini-3-pro-preview until it was shut down on March 9. The successor model gemini-3.1-pro-preview returns:

400 INVALID_ARGUMENT: Computer Use is not enabled for models/gemini-3.1-pro-preview

Minimal repro (Python, google-genai SDK):

from google import genai
from google.genai import types

client = genai.Client(api_key="...")
client.models.generate_content(
    model="gemini-3.1-pro-preview",
    contents=[types.Content(role="user", parts=[types.Part(text="Say hello")])],
    config=types.GenerateContentConfig(
        tools=[types.Tool(computer_use=types.ComputerUse(
            environment=types.Environment.ENVIRONMENT_BROWSER,
        ))],
    ),
)

gemini-3-flash-preview works fine with the same config. Is CU support for 3.1 Pro planned, or should the docs be updated?