Need help: Keyboard input switch works, but it has a flaw.

[dasqeq12]

hello. I need some help.

I have configured hotkeys using Karabiner to switch between keyboard layouts for English, Japanese, and Korean, as I speak all three languages.

It mostly works, but there is one annoying issue: the keyboard input is not applied until I click away from the focused input field (e.g., the address bar in a browser or MS Word). Strangely, the input source changes in the OS immediately after I press the hotkey.
This issue only occurs when I try to switch to languages that use a double-byte character system, such as Japanese or Korean.
Here are the settings and code I have been using. If you have any insights or suggestions, please let me know.

[Setting]

This is the contents of Json from my Complex modification
{
"description": "Right Opt -> japanese",
"manipulators": [
{
"from": {
"key_code": "right_option",
"modifiers": { "optional": ["any"] }
},
"to": [{ "key_code": "right_option" }],
"to_if_alone": [{ "select_input_source": { "language": "ja" } }],
"type": "basic"
}
]
}

[tekezo]

This is a well-known macOS API issue.
https://karabiner-elements.pqrs.org/docs/json/complex-modifications-manipulator-definition/to/select-input-source/

For switching to Japanese, using the japanese_kana key allows the OS to handle it properly at the system level.

{ "key_code": "japanese_kana" }

To switch between CKV (Chinese, Korean, and Vietnamese), using an input source switch shortcut, such as control+space, is a better approach.

[dasqeq12]

Thank you for your help! I've applied your code and it works fine for Japanese. Is there any chance of alternative routes for CKV language? Like using shell command, script, etc.