WiiU Pro controller/Mayflash adapter causing problem?

I’m trying to run Kodi 17.1 on an Nvidia SHIELD TV & am using a WiiU Pro controller with a Mayflash adapter.
The controller works great with the Shield UI, all games/emulators and the rest of the apps.. as soon as I add an add-on or build to Kodi, the problems start. ‘Leanback/Package launcher isn’t responding’ if I leave the message more than a few seconds the Shield will freeze & I’ll have to pull the plug.

Does anyone know what is going on & how it can be fixed (other than buying another controller)

EDIT:

I’ve just installed SPMC & so far so good, none of the above issues or freezing.. wonder what on earth is going on with Krypton?