Cool. I have the MAN to help me. I am sure the problem is NOT with your channel. It is something stupid I did or forget to do.
I have a Wii with 4.1U menu; IOS 15, 21, 36, 38, 222, 249 installed; USB FAT HDD with WBFS files, SD in FAT32 format.
Have been using CFG Usd Loader (v48-> v49...