Super Smash Bros. Ultimate's Nintendo Switch 2 journey isn't going too smoothly as Nintendo asks "please avoid using Mii Fighter in online play as much as possible"
It's not you it's Mii

Nintendo Switch 2 has a ton of free updates available for existing Switch games, with a bunch of first-party Nintendo games getting the rub (especially Pokemon Scarlet and Violet, which desperately needed it). While Super Smash Bros. Ultimate is among the games that run better, it comes with an unexpected downgrade.
Twitter user OatmealDome noticed on the US Eshop page for Super Smash Bros. Ultimate that the game is listed as "Supported – Game progression may be affected in portions of the game" for Switch 2. When you look for more info, it turns out there's not a progression issue; it's actually just that Mii Fighters are not working as they should.
On the store it says, "In online play, when a Switch 2 player and Switch player have been matched, if someone is using Mii Fighter, the match may end immediately," and because of this Nintendo asks that players "please avoid using Mii Fighter in online play as much as possible." So while Mii Fighters do still work online on Switch 2, it's only if you face someone else playing on the new system.
Not only are Mii Fighters having trouble in online crossplay, but Nintendo also notes, "When creating or editing and saving a Mii Fighter, the thumbnail image showing the Mii Fighter may not appear correctly." With the solution being a simple "This may be improved by saving it again."
Nintendo hasn't explained why this happened, although it could be a compatibility issue stemming from the fact that Mii characters are now genderless on Switch 2, I don't know why that would matter when the gender doesn't matter in Smash, but that could have caused the issue. Regardless, Nintendo says that "This is planned to be fixed in the near future," so you can have your Hank Hill vs Sans Undertale brawls online once more.
Sign up to the GamesRadar+ Newsletter
Weekly digests, tales from the communities you love, and more

Scott has been freelancing for over three years across a number of different gaming publications, first appearing on GamesRadar+ in 2024. He has also written for the likes of PC Gamer, Eurogamer, VG247, Play, TechRadar, and others. He's typically rambling about Metal Gear Solid, God Hand, or any other PS2-era titles that rarely (if ever) get sequels.
You must confirm your public display name before commenting
Please logout and then login again, you will then be prompted to enter your display name.