[Bug] Unable to disable automatic attaching current opened file as context for chat

[dcorpStudio]

Copilot chat in VSCode Windows 10 Pro model GPT-5

Describe the bug

The chatbox automatic attaches the opening file with code selected in VSCode as context of my prompt, even when it's totally not involving the prompt, leading to copilot misunderstanding of what I wanted and the wrong edit scope.

For example: I want to update a variable name in entire codebase, result: the variable name is updated only in the unwanted attached context file.
Or even worse: copilot use the attached file to analyze my requests

I've asked the copilot on how to add settings entries to stop that. It suggested me to add the below to settings.json (Ctrl + Shift + P then type Open Settings JSON)

"github.copilot.chat.includeEditorContext": false,
"github.copilot.chat.includeSelection": false,
"github.copilot.chat.includeProblems": false,
"github.copilot.chat.includeTerminal": false,
"github.copilot.chat.includeNotebookContext": false

Done so but no help.

I found that the settings.json also already have the below already

"github.copilot.advanced": {
    "context": {
        "enableEditorContext": false,
        "enableFileContext": false,
        "enableTerminalContext": false
    }
},

But it still act the buggy way above

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It's even worse when the attached context file has no 'x' button to remove

The only way to remove it is to deselect the text in active code file, which is annoying!

Expected behavior

There MUST be a way to easily disable auto context attachment
There MUST be a way to easily remove the unwanted attached context file