vscode: Editor hover does not use reference file encoding until it is opened at least once

• VSCode Version: 1.46.1
• OS Version: macOS 10.15.5

Steps to Reproduce:

Update: Following is reproduction with TypeScript for the sake of minimal setup. But I can confirm that it is at least also reproducible with PHP and Intelephense. My assumption is - it is reproducible regardless of the language.

1. Create empty directory
2. Open it in VSCode and configure your workspace settings like so (this will ensure that VSCode has to be certain about the encoding of the files):

{
  "files.encoding": "windows1251",
  "files.autoGuessEncoding": false
}

1. Create 2 files with windows-1251 encoding (you can do it through VSCode, doesn’t matter)

// foo.ts

/**
 * Возвращает фуу
 */
export function foo(): string {
  return "foo";
}

// test.ts

import { foo } from "./foo";

foo();

1. Close both files/editors (this is important!)
2. Close VSCode
3. Open VSCode
4. Open test.ts
5. Hover over foo()
6. Observe encoding issues
7. Open foo.ts (I assume at this step it actually checks encoding of the file and that’s why it starts working)
8. Go back to test.ts
9. Hover over foo()
10. Observe correctly rendered text

Does this issue occur when all extensions are disabled?: Yes