The Grid - Insert with Tooltip
demo implements a scenario where a user control is displayed inside of a Tooltip when an item is clicked. As demonstrated in this screencast
the tooltip shows as expected.
Would you please modify the attached project, which is a project isolated from the Insert with Tooltip demo, so that it replicates the issue and send it back to us(excluding the bin folder content) in an official support ticket? Thus, we would be able to investigate locally and help you more efficiently.
To run the project you should place the .NET 4.5 version of the Telerik assemblies inside the bin
Once we have a closure in the support thread we can share it here for convenience and better visibility from the community.