Hey! I'm having some trouble with this. I'm trying to play Splatoon 1 with a keyboard and mouse, and the mouse is working, but when I click X to add the keyboard, it doesn't detect me pressing the keyboard at all. (and the keyboard doesn't work ingame). I used HID-TEST on the HB App Store to see if my Wii U is detecting it and it was working, so it's something with the program.
Also, I tried a different mouse and it worked, but the Hiditec GX-12 doesn't work with this for some reason. ( forum doesn't let me link it, just google "Hiditec GX12" and a spanish website will pop up, use the built in google translate in chrome to see it in english =p )
Please excuse my PFP as it synced from twitter (since I made this account using twitter) (superalts has a thing where if you win a giveaway then you get x2 prizes with their pfp)
EDIT: When I tried it months ago, it worked perfectly.
EDIT 2: Using latest version on app store, not sure but I think it's 0.9a (again, not sure. i can check)
EDIT 3: The keyboard is the Microsoft Wired Keyboard 200 in Spanish layout.
EDIT 4: I'm on 5.5.2 too, but I don't understand why this would change anything since HID-TEST detects it.