I run my three accounts on different browsers so I can have them all up at the same time...between Chrome, IE 11, and Edge, Chrome is consistently the slowest. It is also the most affected by lag from graphics-intensive non-browser games. But the real takeaway here is that it is not a problem on Nutaku's end since whenever I get a hung-up loading screen, the issue is always resolved when I reopen the game in a new tab. I don't know how to solve your particular problem, but at least we know where it isn't happening.