Odd error with xamarin forms "Wrong state class, expecting View State but received class ..."

The full error is:
Wrong state class, expecting View State but received class android.widget.ProgressBar$SavedState instead. This usually happens when two views of different type have the same id in the same hierarchy. This view's id is id/0x9. Make sure other views do not use the same id.

I'm seeing this error popping up a few times in Mobile Center (It's occurring on Android 5.1.1) - I don't suppose anyone has had luck tracking this down have they? The full stack trace is:

1
android.view.View.onRestoreInstanceState View.java:15063
2
android.widget.TextView.onRestoreInstanceState TextView.java:4574
3
android.view.View.dispatchRestoreInstanceState View.java:15039
4
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
5
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
6
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
7
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
8
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
9
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
10
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
11
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
12
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
13
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
14
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
15
android.view.ViewGroup.dispatchRestoreInstanceState ViewGroup.java:3198
16
android.view.View.restoreHierarchyState View.java:15017
17
com.android.internal.policy.impl.PhoneWindow.restoreHierarchyState PhoneWindow.java:2297
18
android.app.Activity.onRestoreInstanceState Activity.java:1203
19
android.app.Activity.performRestoreInstanceState Activity.java:1148
20
android.app.Instrumentation.callActivityOnRestoreInstanceState Instrumentation.java:1190
21
android.app.ActivityThread.performLaunchActivity ActivityThread.java:3106
22
android.app.ActivityThread.handleLaunchActivity ActivityThread.java:3243
23
android.app.ActivityThread.access$1000 ActivityThread.java:218
24
android.app.ActivityThread$H.handleMessage ActivityThread.java:1718
25
android.os.Handler.dispatchMessage Handler.java:102
26
android.os.Looper.loop Looper.java:145
27
android.app.ActivityThread.main ActivityThread.java:6914
28
java.lang.reflect.Method.invoke Method.java
29
java.lang.reflect.Method.invoke Method.java:372
30
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run ZygoteInit.java:1404
31
com.android.internal.os.ZygoteInit.main ZygoteInit.java:1199