[bug] fullcalendar invisible on page load finish but appear after an 'action'

[kmoreauSilab]

Hello,

I have a weird bug in my polymer 2 project. I use your component and it works fine but i have a weird bug. When i load my page, the calendar not appear (only header) and if i click on prev/next month action button, the calendar appear. If i open my dev console, the calendar will also appear !
Do you have any ideas about this problem ? :) thank