After some more testing I was able to reproduce the issue with version 2015.1.401 of UI for WPF. However, the issue doesn't appear in the latest version of our controls. This is why I recommend you to update your dlls. This way you can take advantage of the newest features and bug fixes.
As for the attachment, the forum posts allow only the attachment of images. If you want to send an archive with the code, you could open a new support ticket. Or you could include a few code snippets in your posts that can be used for assembling a runnable project that reproduces the issue.
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and share your thoughts.