Slider doensn't work on page load

[vanool]

First of all awesome that you made these sliders!

Unfortunately I have a issue with the slider. If you go to this link http://nielsvt.remvoo.com/ and then click on portfolio you'll see the slider at the bottom of the page.

The problem where i'm dealing with is that the slider doesn't work on page load, but when you resize the browser the slider suddenly works. The only thing I changed is: I added min-height: 250px to swiper.min.css else the slider wouldn't display on the website.