I reproduces this behavior on the following Dojo snippet
, It is caused by not having the image loaded initially when the tooltip becomes visible. When the image is loaded, tooltip spans out of the bottom of the screen. I am afraid that there is no workaround for this scenario. Only setting tooltip height prevents this behavior. It would be helpful if you provide a Dojo snippet of your scenario to check if there is a possible workaround for it.
Get quickly onboarded and successful
with your Telerik and/or Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.