Summary

When an IME (Input Method Editor, e.g. Japanese IME) is active, pressing the prefix key (Ctrl+B) works correctly, but the subsequent command key (n, p, c, d, etc.) is captured by the IME instead of being handled by psmux.

Steps to Reproduce

1. Start a psmux session
2. Enable an IME (e.g. toggle Japanese input with the Hankaku/Zenkaku key)
3. Press Ctrl+B — the prefix is recognized normally
4. Press n — instead of switching to the next window, the IME opens its candidate/composition window

Expected Behavior

After the prefix key is accepted, the next keystroke should be treated as a psmux command key regardless of the IME state.

Actual Behavior

Even after the prefix key is accepted, the IME intercepts alphabetic keystrokes and treats them as composition input.

Context

For users who frequently type in CJK languages while also switching windows/panes, having to toggle the IME off before every prefix sequence adds significant friction. It would be very helpful if psmux could temporarily suppress or bypass the IME after accepting the prefix key, so that the following command keystroke is always passed through directly.

Environment

• OS: Windows 11
• IME: Microsoft Japanese IME
• psmux: v3.3.4 (scoop)