From Nintendo Official page:
A system update (9.0 NUP) is required in order to use Super Nintendo Entertainment System Controllers with your Nintendo Switch console.
https://mynintendostore.nintendo.co.uk/catalog/product/view/id/668
A system update (9.0 NUP) is required in order to use Super Nintendo Entertainment System Controllers with your Nintendo Switch console.
https://mynintendostore.nintendo.co.uk/catalog/product/view/id/668