diff --git a/src/popover/animations/ios.enter.ts b/src/popover/animations/ios.enter.ts
index 8d68957..c0c108e 100644
--- a/src/popover/animations/ios.enter.ts
+++ b/src/popover/animations/ios.enter.ts
@@ -102,6 +102,7 @@ export const iosEnterAnimation = (baseEl: HTMLElement, opts: any = {}): Animatio
     results.referenceCoordinates,
     referenceSizeEl?.getBoundingClientRect(),
     isReplace,
+    opts.preserveHorizontalAlignment === true,
   );
   // A replacing surface grows inward from the button's edge, not its center.
   const preferredLeft =
diff --git a/src/popover/utils.spec.ts b/src/popover/utils.spec.ts
index a18137c..a69aa79 100644
--- a/src/popover/utils.spec.ts
+++ b/src/popover/utils.spec.ts
@@ -4,10 +4,31 @@ import { calculateWindowAdjustment, getIndexOfItem, getNextItem, getPopoverPosit
 
 describe('popover utilities', () => {
   it.each(['left', 'right', 'start', 'end'] as const)('preserves the vertical anchor alignment for side=%s', (side) => {
-    const position = calculateWindowAdjustment(side, 120, 100, 5, 440, 636, 200, 52, 8, 'right', 'center');
+    const position = calculateWindowAdjustment(
+      side,
+      120,
+      100,
+      5,
+      440,
+      636,
+      200,
+      52,
+      8,
+      'right',
+      'center',
+      undefined,
+      undefined,
+      false,
+      true,
+    );
     expect(position.top).toBe(120);
-    expect(calculateWindowAdjustment(side, -4, 100, 5, 440, 636, 200, 52, 8, 'right', 'center').top).toBe(5);
-    expect(calculateWindowAdjustment(side, 620, 100, 5, 440, 636, 200, 52, 8, 'right', 'center').top).toBe(579);
+    expect(calculateWindowAdjustment(side, 120, 100, 5, 440, 636, 200, 52, 8, 'right', 'center').top).toBe(128);
+    expect(
+      calculateWindowAdjustment(side, -4, 100, 5, 440, 636, 200, 52, 8, 'right', 'center', undefined, undefined, false, true).top,
+    ).toBe(5);
+    expect(
+      calculateWindowAdjustment(side, 620, 100, 5, 440, 636, 200, 52, 8, 'right', 'center', undefined, undefined, false, true).top,
+    ).toBe(579);
   });
 
   it('navigates only relative to ion-item elements', () => {
diff --git a/src/popover/utils.ts b/src/popover/utils.ts
index 5700079..e2cb4fc 100644
--- a/src/popover/utils.ts
+++ b/src/popover/utils.ts
@@ -612,11 +612,13 @@ export const calculateWindowAdjustment = (
   triggerCoordinates?: ReferenceCoordinates,
   eventElementRect?: DOMRect,
   isReplace: boolean = false,
+  preserveHorizontalAlignment: boolean = false,
 ): PopoverStyles => {
   const triggerTop = triggerCoordinates ? triggerCoordinates.top + triggerCoordinates.height : bodyHeight / 2 - contentHeight / 2;
   const triggerHeight = triggerCoordinates ? triggerCoordinates.height : 0;
   let left = coordLeft;
-  const horizontal = side === 'left' || side === 'right' || side === 'start' || side === 'end';
+  // Projected rail controls opt in; ordinary popovers retain their existing margin.
+  const horizontal = preserveHorizontalAlignment && (side === 'left' || side === 'right' || side === 'start' || side === 'end');
   let top = !isReplace ? coordTop + (horizontal ? 0 : POPOVER_IOS_BODY_MARGIN) : coordTop - triggerHeight;
   if (horizontal && !isReplace) top = Math.max(bodyPadding, Math.min(top, bodyHeight - bodyPadding - contentHeight));
   let bottom;