SFPopupLayout produces NullReference on IsOpen = true after navigation (xamarin forms)

On first navigating to this page, there is no issue, and the popup can be opened/closed multiple times. After navigating back, then forward again to the same page, the popup produces a NullReference exception when IsOpen changes to true. All other controls on the page work fine, including an SfDataGrid. I tried removing the binding to IsOpen and using .Show(), but that produced the same issue. This is with version 16.3.0.29 on iOS 12, xamarin forms version 3.3.0.967583. Have also tested with rowspan = 2. 

Stacktrace:

"  at Syncfusion.XForms.iOS.PopupLayout.SfPopupLayout.ResizePopupView () [0x001e4] in <1356613810c24590a725cab6be10944b>:0 \n  at Syncfusion.XForms.iOS.PopupLayout.SfPopupLayout.DisplayPopup () [0x00026] in <1356613810c24590a725cab6be10944b>:0 \n  at Syncfusion.XForms.iOS.PopupLayout.SfPopupLayout.set_IsOpen (System.Boolean value) [0x00024] in <1356613810c24590a725cab6be10944b>:0 \n  at Syncfusion.XForms.iOS.PopupLayout.RendererHelper.MapSfPopupLayoutProperties (System.String propertyName, Syncfusion.XForms.PopupLayout.SfPopupLayout formsPopupLayout, Syncfusion.XForms.iOS.PopupLayout.SfPopupLayout nativePopupLayout) [0x0003c] in <1356613810c24590a725cab6be10944b>:0 \n  at Syncfusion.XForms.iOS.PopupLayout.PopupLayoutDependencyService.MapSfPopupLayoutProperties (System.String propertyName, Syncfusion.XForms.PopupLayout.SfPopupLayout formsPopup) [0x00010] in <1356613810c24590a725cab6be10944b>:0 \n  at Syncfusion.XForms.PopupLayout.SfPopupLayout.OnIsOpenChanged (Xamarin.Forms.BindableObject bindable, System.Object oldValue, System.Object newValue) [0x00042] in <6491071ab4dc4290b46b78b9473c7fd0>:0 \n  at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent) [0x00120] in D:\\a\\1\\s\\Xamarin.Forms.Core\\BindableObject.cs:625 \n  at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x0015b] in D:\\a\\1\\s\\Xamarin.Forms.Core\\BindableObject.cs:417 \n  at Xamarin.Forms.BindingExpression.ApplyCore (System.Object sourceObject, Xamarin.Forms.BindableObject target, Xamarin.Forms.BindableProperty property, System.Boolean fromTarget) [0x00225] in D:\\a\\1\\s\\Xamarin.Forms.Core\\BindingExpression.cs:173 \n  at Xamarin.Forms.BindingExpression.Apply (System.Boolean fromTarget) [0x0003e] in D:\\a\\1\\s\\Xamarin.Forms.Core\\BindingExpression.cs:57 \n  at Xamarin.Forms.BindingExpression+BindingExpressionPart.b__49_0 () [0x00000] in D:\\a\\1\\s\\Xamarin.Forms.Core\\BindingExpression.cs:615 \n  at Foundation.NSAsyncActionDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.10/src/Xamarin.iOS/Foundation/NSAction.cs:152 "