We reproduced the issue. Thank you for reporting this bug, it helps us in improving our products. I am glad to update your points for reporting this abnormal behavior of our RadDocking control. We will investigate the cause for this issue and we will fix it in one of our future releases. You can track this progress in our Public Issue Tracking System (PITS) with Issue ID = 4112.
Unfortunately, we cannot provide a workaround at this stage. Sorry for any inconvenience caused.
the Telerik team
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