A plain pump() between enterText(To) and enterText(Subject) does not prevent the _zOrderIndex assertion: hide() is called twice synchronously during the focus-dispatch triggered by the second enterText(). Fix: explicitly call primaryFocus?.unfocus() after the To field, then pump(300ms) so RawAutocomplete's OverlayPortal closes via a single FocusNode notification. By the time Subject takes focus the overlay is already hidden — no second hide() fires. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>