Solved XF.setupHtmlInsert has different behavior in XF 2.2 and XF 2.3.

[NikitOS]

In XF 2.2, if a jQuery object is passed as the second argument (onReady) to the XF.setupHtmlInsert method, the innerHTML of the target was replaced with the outerHTML of the elements in the jQuery collection (via Node.appendChild).
In XF 2.3, if an HTMLElement object is passed as the second argument, the innerHTML of the target is replaced with the innerHTML of the passed element.

Continue reading...