IsolatedStorageException in WebViewRenderer for WinPhone

Hello,

I use Xamarin.Forms 1.4.2.6355
I have a tabbedPage which displays 2 small webviews (to display simple rich texts content)
I have the following exception that doesn't always occur (roughly 50%) only on win phone (android and ios are fine)

System.IO.IsolatedStorage.IsolatedStorageException: Operation not permitted on IsolatedStorageFileStream.

at System.IO.IsolatedStorage.IsolatedStorageFileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, IsolatedStorageFile isf)
at System.IO.IsolatedStorage.IsolatedStorageFile.OpenFile(String path, FileMode mode, FileAccess access)
at Xamarin.Forms.WP8PlatformServices._IsolatedStorageFile.OpenFileAsync(String path, FileMode mode, FileAccess access)
at Xamarin.Forms.Platform.WinPhone.WebViewRenderer.d__a.MoveNext()

My assumption is that in the webViewRenderer xamarin tries to save a file, and maybe as I have several webviews, the name of the file might be the same :
string fileName = string.Format("formslocal_{0}.html", (object) DateTime.Now.Ticks);

Can you confirm ? Is there a workaround ?