TUI intermittently delays or drops keystrokes on macOS while shell and --mini remain responsive

[johncarterlives]

Description

The full terminal TUI intermittently delays or drops keyboard input on macOS. The shell remains smooth in the same Tabby pane after suspending OpenCode, and opencode --mini is substantially more responsive.

The problem reproduces with both Tabby terminal renderers (xterm-webgl and canvas), including a fresh full-TUI session and light worktree cleanup activity over about 30 minutes. It also occurs while OpenCode is near idle (about 0.6-2.1% CPU with the system about 73% idle), so it is not explained by sustained CPU, memory, disk, swap, or thermal pressure.

This resembles #265, but that issue was closed after a fix and a maintainer requested a new issue if the symptom returned. I found no active report matching this current macOS/full-TUI/renderer-independent reproduction.

Plugins

opencode-aidevops. The issue reproduces in a fresh session, but has not yet been tested with --pure.

OpenCode version

1.18.2 and 1.18.3

Steps to reproduce

1. Open a fresh Tabby pane.
2. Start a fresh normal opencode session.
3. Type continuously in the full TUI; input intermittently appears late or does not appear.
4. Suspend OpenCode with Ctrl-Z and type in the shell in the same pane; shell input is smooth.
5. Compare with opencode --mini; input is substantially more responsive.
6. Repeat after switching Tabby between WebGL and canvas; the full-TUI lag reproduces with both.

Screenshot and/or share link

No screenshot; the visible symptom is delayed or missing keystrokes.

Operating System

macOS 26.5.2, Apple silicon (arm64, M4 Pro)

Terminal

Tabby 1.0.234 / Electron 38.2.2; reproduced with both xterm-webgl and canvas

---

aidevops.sh v3.32.133 plugin for OpenCode v1.18.3

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Chat input box has severe typing delay, other input boxes work normally #36486: Chat input box has severe typing delay (similar symptom of keystroke lag in the TUI, though reported on Windows desktop)
• TUI input thread freezes for 5-10 s while Zed editor-context poll waits on SQLite lock #28123: TUI input thread freezes for 5-10 s (TUI input freezing, different root cause but similar symptom)
• macOS: chat input becomes barely usable after the first response #17001: macOS chat input becomes barely usable after the first response (closed; macOS-specific input responsiveness issue)

You already referenced #265 — thank you for checking first. The issues above are the closest remaining open/recent reports.