Firefox - resize browser or reorient mobile doesn't refresh display properly

Hello,

I notice a problem I don't know how to fix.

In some cases, resize or reorient doesn't refresh the display properly.

This can be tested by activating mobile simulator on Firefox with Apple iPad Air 2 device on the url :
http://test.wedding-table-plan.com/
(login : canvas / pass : canvas)

And then use "reorient" button to switch orientation.

Here you see that when reorienting to landscape mode, the display of the carousel is not adapting well.
I have attached here the expected display when refreshing the page.

I hope you have an idea on what I could do to fix this :)
Thank you.

(PS : sorry for this splitted post, but it seems like I could not edit my previous post... Thank you !)