Cannot access a disposed object

This is on a Xamarin Forms app.
Android: 9
Android Build: PKQ1.190118.001
Manufacturer: vivo
Model: vivo 1727

```
Xamarin Exception Stack:
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'Android.App.NotificationManager'.
at Java.Interop.JniPeerMembers.AssertSelf (Java.Interop.IJavaPeerable self) [0x00029] in <4d2af34ca2694c37a4ea3d8074f2f66b>:0
at Java.Interop.JniPeerMembers+JniInstanceMethods.InvokeVirtualVoidMethod (System.String encodedMember, Java.Interop.IJavaPeerable self, Java.Interop.JniArgumentValue* parameters) [0x00000] in <4d2af34ca2694c37a4ea3d8074f2f66b>:0
at Android.App.NotificationManager.Cancel (System.Int32 id) [0x00022] in <519a5f3aaae444f4b50cf623ff03eb78>:0
at Plugin.Toasts.NotificationBuilder.TimerFinished (System.String id, System.Boolean cancel, System.Boolean allowTapInNotificationCenter) [0x00028] in :0
at Plugin.Toasts.NotificationBuilder+<>c__DisplayClass23_1.b__0 (System.Object x) [0x00031] in :0
at System.Threading.Timer+Scheduler.TimerCB (System.Object o) [0x00007] in <254b242c97154351aae8e0970082105e>:0
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem () [0x00008] in <254b242c97154351aae8e0970082105e>:0
at System.Threading.ThreadPoolWorkQueue.Dispatch () [0x00074] in <254b242c97154351aae8e0970082105e>:0
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () [0x00000] in <254b242c97154351aae8e0970082105e>:0
```