All loading panels are shown, because all controls are being updated. If you want to display only one RadAjaxLoadingPanel, you can do one of the following:
1. Use one RadAjaxLoadingPanel for the whole page:
2. Use the RadAjaxManager's OnRequestStart client event and show a RadAjaxLoadingPanel manually over the desired portion of the page, depending on which control is the AJAX initiator:
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