But was: <System.NotSupportedException: Specified method is not supported.
at System.Collections.Immutable.ImmutableArray`1.System.Collections.ICollection.get_SyncRoot()
at Gu.Reactive.Internals.ListExt.SyncRootOrDefault(IEnumerable source, Object default)
at Gu.Reactive.ReadonlyViewBase`2.Refresh(IReadOnlyList`1 changes)
at Gu.Reactive.ReadOnlyFilteredView`1.Update(Chunk`1 changes)
at System.Reactive.AnonymousSafeObserver`1.OnNext(T value) in D:\a\1\s\Rx.NET\Source\src\System.Reactive\AnonymousSafeObserver.cs:line 44
