Error beetween fullcalendar and webuipopover during event render element.pover

[Gmanunta]

I'm using webuipover with js fullcalendar; in eventRender

this is my code

eventRender: function (event, element) {
element.webuiPopover({
container: schedulerManager.calendar,
content: event && event.GetTooltip && event.GetTooltip(),
type: 'html',
trigger: 'hover',
placement: 'auto-bottom',
cache: false,
autoHide: 20000,
delay: {
show: 1000,
hide: 100
},
onShow: function ($element) {
var a = "";
} // callback after show
});
element.bind("dblclick", () => window.open(event.GetUrl(), "_blank"));
//element.bind("click", (e) => { alert("ok" + e.which); zzz = e });
element.bind("contextmenu", (jsEvent) => {
schedulerManager.menu.ShowEventMenu(event, jsEvent.clientX, jsEvent.clientY);
});
},

if I set up parameter placement: 'auto-bottom', the webuipopover control render the tooltip on top left of the pagethat that it is wrong, if I use the the placement: 'auto-top' the webuipopover control works correctly