sometimes the target input method will stuck on loading after swiching

[kanoto]

Hi, I used to using Karabiner to customize the shortcuts to trigger im-select switching input methods, like the following one, which uses right_shift + s to switch to squirrel input method:

{
  "from": {
        "key_code": "s",
        "modifiers": {
            "mandatory": [
                "right_shift"
            ]
        }
    },
    "to": [
        {
            "shell_command": "/usr/local/bin/im-select im.rime.inputmethod.Squirrel.Hans"
        }
    ],
    "type": "basic"
},

However, I found that sometimes after switching, the input method will stuck on loading, showing some dots only ..... (the following is another Japanese input method, while this issue has occurred with all input methods except native English)

Whereas manually switching by clicking on the input method will never cause this.

Any idea about this issue?