I'm sorry to hear about the issues you've experienced, hope they haven't caused much inconvenience. This behavior seems to be caused by the rendering of layouts on the frontend, where content from the parent masterpage will get loaded first before the content on the child masterpages. What you can try is to provide a placeholder in the parent masterpage for each control that you'll be placing in the child masterpages / page using that template. When specifying a valid placeholder in the parent, then all you need to do is place a 100% layout element in that place on the child matserpage and put your control there, this should fix the problems.We had a bug logged for this issue, and I have just verified that a fix has been developed and in in a Ready for Test stage, if it passes successfully it will be included in one of the upcoming releases for sure.
the Telerik team
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