Map not loading on pageload, after 'inspect element' it appears


I'm using the Kleo Next Level theme. ( )

In my pages I use 'tabs' and in one of these tabs I have used the Maps plugin.

When I load the page, the map doesn't show, just a grey fraction (like 10px wide) when i right-click it and click inspect element. The maps, pops up in its place like it's supposed to.

I have no idea why it doens't load op the pageload. Could you please help me?