It only works after I go to home and open it again. (After a few times of this.)
Explorer is lagging

I can't test right now, since I'm on a spotty/slow connection, but just because your local Internet connection seems fine, doesn't mean there's not an issue between you and the site.
There could also be a browser specific issue. What browser and version are you on?
For Me, whenever I click Explorer under more on a PC, it lags.
Please fix.