As I said, when you set IsSticky="true", the RadAjaxLoadingPanel is displayed where you have placed it in the page markup. In addition, you should take care of the control's width, height and positioning yourself.
>> Should I treat the sticky loading panel as an updated control (as below?)
>> I do not want to set the DefaultLoadingPanelID for the entire RadAjaxManager.
You don't have to.
>> I have also tried to set the sticky loading panel as LoadingPanelID for any random updated control, but this only leads to a white page while loading. What am I doing wrong?
Probably you have tried to implement a loading panel which spans over the whole page? However, you should either set the control's Skin property, or use a loading template (e.g. add an animated image, etc).
Please inspect the provided help articles once again, especially this one:
If you need further assistance, please send a runnable web page and explain what exactly are you trying to do.
All the best,
the Telerik team
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