For Windows Server 2019/2022 English OS or Windows 10/11 as VDA, CWA Windows Client uses Microsoft Pinyin IME to input simplified Chinese, Microsoft Bopomofo IME to input traditional Chinese, or Microsoft Japanese IME to input Japanese, keyboard sync mode is configured as "Sync only once" in Advanced Preferences -> "Keyboard and Language Bar", start the virtual desktop session.

• Microsoft Pinyin IME, Microsoft Bopomofo IME, or Japanese Microsoft IME will be installed in the session. But the IME cannot change to Chinese ("中") input mode or Hiragana mode through the shortcut or by clicking the input mode icon.
• The message "Simplified Chinese IME dictionaries are not ready yet", "Traditional Chinese IME dictionaries are not ready yet" or “Japanese IME is not ready yet” popped up.

Perform the following workaround,

• To input Simplified Chinese, install Microsoft Pinyin IME through UI configuration "Settings" -> "Time & Language" -> "Language" -> "Add a Language" -> “Chinese (Simplified, China)”
• To input Traditional Chinese, install Microsoft Bopomofo IME through UI configuration Settings" -> "Time & Language" -> "Language" -> "Add a Language" -> “Chinese (Traditional, Taiwan)”
• To input Japanese, install Microsoft Japanese IME through UI configuration Settings" -> "Time & Language" -> "Language" -> "Add a Language" -> “Japanese”

OR

• Use DISM command guide in https://docs.microsoft.com/en-us/troubleshoot/windows-server/deployment/chinese-ime-dictionaries-not-ready