RadTileList determines the tiles positions in the available rows and columns on the client, after the HTML renders. With many tiles and a slow browser, you could notice a rearrangement of the tiles when the page loads.
If this is not what you see, please explain the case in more detail. It would also help if you add a video that shows the problem and the code that leads to it.
Also, if the custom scripts you have are what causes the tileList to repaing, please examine them and see if they are needed.
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