Ctrl+click on a sidebar session opens a new window instead of a second pane (Windows)

Environment: Windows 11 Home (10.0.26200) · Claude Code 2.1.240 · desktop app on latest as of 2026-09-10

https://code.claude.com/docs/en/desktop says:

"To view two sessions at once, hold Cmd on macOS or Ctrl on Windows and click a session in the sidebar. The session opens in a second pane alongside the one you already have open."

On my machine Ctrl+left-click opens the session in its own separate window instead of a second pane.

Repro: single session open, no split active → Ctrl+left-click any other session in the sidebar.
Expected: second pane in the same window.
Actual: a new window.

Right-click → "Open in split view" on the same session works correctly, so the split capability is present — it's the modifier-click path that misbehaves.