diff --git a/components/calendar/__tests__/calendar-app.test.tsx b/components/calendar/__tests__/calendar-app.test.tsx
index 843e003d9..323b411a3 100644
--- a/components/calendar/__tests__/calendar-app.test.tsx
+++ b/components/calendar/__tests__/calendar-app.test.tsx
@@ -126,6 +126,18 @@ describe('CalendarApp keyboard shortcuts', () => {
     fireEvent.keyDown(document.body, { key: 'm', code: 'KeyM' });
     expect(useCalendarStore.getState().viewMode).toBe('month');
   });
+
+  // New 6: the preview opened on top of the open editor.
+  it('opens no hover preview while an editor is open', async () => {
+    setUp([makeEvent(), makeEvent({ id: 'e2', uid: 'u2', title: 'Retro', start: '2026-10-13T14:00:00' })]);
+    renderApp();
+    fireEvent.click(screen.getAllByRole('button', { name: /Standup/ })[0]);
+    fireEvent.click(await screen.findByRole('button', { name: 'events.edit' }));
+    await screen.findByRole('dialog', { name: 'events.edit' });
+    fireEvent.mouseEnter(screen.getAllByRole('button', { name: /Retro/ })[0]);
+    await new Promise((r) => setTimeout(r, 50));
+    expect(screen.queryByRole('dialog', { name: 'Retro' })).toBeNull();
+  });
 });
 
 
diff --git a/components/calendar/calendar-app.tsx b/components/calendar/calendar-app.tsx
index db516779c..7eca930b6 100644
--- a/components/calendar/calendar-app.tsx
+++ b/components/calendar/calendar-app.tsx
@@ -91,6 +91,7 @@ import { useCalendarEventSearch } from "@/hooks/use-calendar-event-search";
 import { CalendarSearchField, CalendarSearchResults } from "@/components/calendar/calendar-search";
 import { useProInterfaceActive } from "@/components/pro/pro-interface-redirect";
 import { useCalendarLocale } from "@/hooks/use-calendar-locale";
+import { useHoverPreviewGate } from "@/hooks/use-hover-preview-gate";
 import {
   computeScrollWindow, fixedScrollWindowState, freshScrollWindowState, growScrollWindow, normalizeScrollWindowState,
   scrollWindowContains, type CalendarFocus, type ScrollViewMode, type ScrollWindowOptions,
@@ -842,16 +843,20 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
     [closeDetail, openEmptyContextMenu],
   );
 
+  // No preview over an open editor, card or dialog, nor after one closed
+  // until the pointer moves.
+  const canHoverPreview = useHoverPreviewGate(showEventModal || showTaskModal || detailPinned || quickDraft !== null);
+
   const handleHoverEvent = useCallback((event: CalendarEvent, anchorRect: DOMRect) => {
     if (isMobile) return;
     if (detailPinnedRef.current) return;
     if (calendarHoverPreview === 'off') return;
     if (hoverTimerRef.current) { clearTimeout(hoverTimerRef.current); hoverTimerRef.current = null; }
-    // Don't show hover popover if the sidebar is already open for this event
-    if (showEventModal && editEvent?.id === event.id) return;
+    if (!canHoverPreview()) return;
     if (calendarHoverPreview === 'delay-500ms' || calendarHoverPreview === 'delay-1s' || calendarHoverPreview === 'delay-2s') {
       const ms = calendarHoverPreview === 'delay-500ms' ? 500 : calendarHoverPreview === 'delay-1s' ? 1000 : 2000;
       hoverTimerRef.current = setTimeout(() => {
+        if (!canHoverPreview()) return;
         setDetailEvent(event);
         setDetailAnchorRect(anchorRect);
       }, ms);
@@ -859,7 +864,7 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
       setDetailEvent(event);
       setDetailAnchorRect(anchorRect);
     }
-  }, [isMobile, calendarHoverPreview, showEventModal, editEvent]);
+  }, [isMobile, calendarHoverPreview, canHoverPreview]);
 
   const handleHoverLeave = useCallback(() => {
     if (hoverTimerRef.current) { clearTimeout(hoverTimerRef.current); hoverTimerRef.current = null; }
diff --git a/hooks/__tests__/use-hover-preview-gate.test.ts b/hooks/__tests__/use-hover-preview-gate.test.ts
new file mode 100644
index 000000000..6de1c03c8
--- /dev/null
+++ b/hooks/__tests__/use-hover-preview-gate.test.ts
@@ -0,0 +1,43 @@
+import { renderHook } from '@testing-library/react';
+import { describe, it, expect } from 'vitest';
+import { useHoverPreviewGate } from '../use-hover-preview-gate';
+
+// The hover preview opened on top of the open editor, and by itself after
+// a dialog closed with the pointer resting on an event.
+
+function move(x: number, y: number) {
+  window.dispatchEvent(new MouseEvent('pointermove', { clientX: x, clientY: y }));
+}
+
+describe('useHoverPreviewGate', () => {
+  it('lets a preview open when nothing is open', () => {
+    const { result } = renderHook(() => useHoverPreviewGate(false));
+    expect(result.current()).toBe(true);
+  });
+
+  it('holds previews back while an editor is open, and after it closed until the pointer moves', () => {
+    const { result, rerender } = renderHook(({ open }) => useHoverPreviewGate(open), { initialProps: { open: true } });
+    move(100, 100);
+    expect(result.current()).toBe(false);
+    rerender({ open: false });
+    expect(result.current()).toBe(false);
+    move(101, 101);
+    expect(result.current()).toBe(false);
+    move(140, 120);
+    expect(result.current()).toBe(true);
+  });
+
+  it('holds previews back while a modal dialog is on the page, and after it closed', async () => {
+    const { result } = renderHook(() => useHoverPreviewGate(false));
+    move(10, 10);
+    const dialog = document.createElement('div');
+    dialog.setAttribute('aria-modal', 'true');
+    document.body.appendChild(dialog);
+    expect(result.current()).toBe(false);
+    dialog.remove();
+    await new Promise((r) => setTimeout(r, 0));
+    expect(result.current()).toBe(false);
+    move(60, 60);
+    expect(result.current()).toBe(true);
+  });
+});
diff --git a/hooks/use-hover-preview-gate.ts b/hooks/use-hover-preview-gate.ts
new file mode 100644
index 000000000..430a2a873
--- /dev/null
+++ b/hooks/use-hover-preview-gate.ts
@@ -0,0 +1,72 @@
+import { useCallback, useEffect, useRef } from "react";
+import { isContextMenuOpen } from "@/components/ui/context-menu";
+
+/** How far the pointer has to move before a preview may open again. */
+const MOVE_THRESHOLD = 4;
+
+const MODAL_SELECTOR = '[aria-modal="true"]';
+
+/**
+ * Decides whether a hover preview may open. Not while an editor, a card,
+ * a menu or a dialog is open (`overlayOpen` plus any modal on the page),
+ * and not after one closed until the pointer really moves: the pointer
+ * resting where the dialog was otherwise "hovers" the event under it and
+ * the preview opens by itself.
+ */
+export function useHoverPreviewGate(overlayOpen: boolean): () => boolean {
+  const overlayOpenRef = useRef(overlayOpen);
+  const pointer = useRef<{ x: number; y: number } | null>(null);
+  // Where the pointer was when previews were held back; null when free.
+  const heldAt = useRef<{ x: number; y: number } | null>(null);
+
+  const hold = useCallback(() => {
+    heldAt.current = pointer.current ?? { x: Number.NaN, y: Number.NaN };
+  }, []);
+
+  useEffect(() => {
+    const onMove = (e: PointerEvent | MouseEvent) => {
+      const at = { x: e.clientX, y: e.clientY };
+      pointer.current = at;
+      const held = heldAt.current;
+      if (!held) return;
+      // Position unknown when it was held: the first move frees it.
+      if (Number.isNaN(held.x) || Math.hypot(at.x - held.x, at.y - held.y) > MOVE_THRESHOLD) {
+        heldAt.current = null;
+      }
+    };
+    window.addEventListener("pointermove", onMove, { passive: true });
+    return () => window.removeEventListener("pointermove", onMove);
+  }, []);
+
+  // An editor, card or quick editor of the calendar closing.
+  useEffect(() => {
+    const was = overlayOpenRef.current;
+    overlayOpenRef.current = overlayOpen;
+    if (was && !overlayOpen) hold();
+  }, [overlayOpen, hold]);
+
+  // Any other dialog (a confirm, import, shortcuts) portalled onto <body>.
+  useEffect(() => {
+    if (typeof MutationObserver === "undefined") return;
+    const observer = new MutationObserver((records) => {
+      for (const record of records) {
+        for (const node of record.removedNodes) {
+          if (node instanceof Element && (node.matches(MODAL_SELECTOR) || node.querySelector(MODAL_SELECTOR))) {
+            hold();
+            return;
+          }
+        }
+      }
+    });
+    observer.observe(document.body, { childList: true });
+    return () => observer.disconnect();
+  }, [hold]);
+
+  return useCallback(() => {
+    if (overlayOpenRef.current || isContextMenuOpen() || document.querySelector(MODAL_SELECTOR)) {
+      hold();
+      return false;
+    }
+    return heldAt.current === null;
+  }, [hold]);
+}