This is not a problem we are aware of. We would need some time to test similar cases to see if we can find something.
For the time being I can suggest that you
- try overriding its position to fixed to see if this helps
- change the ContentScrolling to Both or Y since ,if you have a lot of content, it will always have some scrollbars
- try the RadNotification control in its place to see if it behaves better. You can place arbitrary content in its ContentTemplate, and setting the UpdateInterval to 0 should prevent if from initiating automated updates.
- consider the RadWindow control if you have a lot of content - having it load a separate page can be helpful. It can be pinned so that it does not scroll with the rest of the page.
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