Lexical version: 0.36.2 (also reproducible on the latest https://playground.lexical.dev )

Steps To Reproduce

1. Open a Lexical editor on Safari (macOS)
   • Reproducible on the latest https://playground.lexical.dev as well
2. Switch to a Japanese IME (or another IME-based input method such as Chinese/Korean)
3. Type some text and confirm the composition (e.g. type "あいうえお")
4. Select the text using Shift+Arrow keys or Cmd+A
5. Press the Delete (Backspace) key

Link to code example: https://playground.lexical.dev

The current behavior

The selected text is not properly deleted. Depending on the case, only the last character is removed, or only the first few characters are deleted, instead of the entire selection being cleared.

This issue does not occur with direct-input (non-IME) languages such as English.

The expected behavior

The selected text should be fully deleted when pressing Delete, regardless of whether the text was entered via IME composition.

Impact of fix

• This affects all users who use IME-based input languages (Japanese, Chinese, Korean, etc.) on Safari (macOS).
• Basic text editing operations (select + delete) are broken, significantly degrading the editing experience for these users.
• Safari has a notable market share on macOS, and CJK languages collectively represent a large user base.