The ContentScrolling property does not take effect under IE10. The end result is that the control behaves as if the property has its Default value (i.e. the browser will handle the overflow of the elements, which means large content will stretch the tooltips).
Anyone experiencing the same issue with IE10 and IE11 can switch to Lightweight render mode in order to have this resolved.
We did not manage to reproduce this issue with the current Telerik UI for ASP.NET AJAX (R1 SP1 2016)
Instead of using the ContentScrolling radToolTip property we made the div/content inside the tooltip scrollable (style="overflow:auto;") Because on October 1st the issue is still here with IE10 That a quick workaround but it works
We need this feature. It's very important. Thanks