Nintendo has banned multiple Switch 2 gamers from all online services for using a MIG Switch flash cart. The MIG Switch, which allows users to play backed-up copies of Switch games, has been at the heart of controversy since its introduction in early 2024, as it is a tool that has been used for pirating Nintendo Switch games.https://www.notebookcheck.net/Nintendo-bans-users-of-MIG-Switch-flash-cart-on-Switch-2.1039234.0.html
Nintendo are outright pricks, it's that simple.
Using unofficial game card which mostly used to play unofficially retrieved game software, on a platform which notoriously famous for banning people on legal reasons. What can possibly go wrong?