I have a similar issue on a normal Wii. But USB loader 2.0 works just fine where as USB loader 3.0 will hang at initializing HDD unless it's unplugged and I plug it in during the 20 seconds it gives you to plug it in then it will load.
That video from Facebook where the lady blends up dry spaghetti noodles to make fresh noodles.... Even though just you know using flour would be better lol