Non-English IME does not work depending on the website

Depending on the web site, non-english IME does not work.

For example:

In a Word document on Microsoft 365 (https://www.microsoft365.com/) :
  - Direct input via Japanese IME was not possible while English can be directly input.
  - Copying/pasting Japanese words was possible.

In Google document (https://docs.google.com/document/)  :
  - Both of direct input via IME and copy/paste were possible.

In the search box on Qt Group Website (https://www.qt.io/)

  - Both of direct input via IME and copy/paste were possible.

This issue can be reproduced with following setups:

Application:
  WebEngine Widgets Simple Browser included in Qt 6.6.1

Kit:
  Desktop Qt 6.6.1 MSVC2019 64bit

OS:
  Windows 11