Yeah, that's what I figured, I didn't think it was NUSspli's fault, guess getting a lan adapter would be the best option for it.
So this is slightly off-topic but like. Does it matter which USB ports you plug things into on Wii U? I know there's front ports and back ports, and I'm just wondering if each port has equal functions or not. Like can I plug the external hdd into any of them, and the lan adapter into any of them? Or the GameCube controller adapter, for instance? I mean that I can just unplug while using NUSspli but if I was playing Smash online it's a different story.