https://wccftech.com/super-mario-maker-2-first-update-fixes/

A new update has been released for Super Mario Maker 2, the new entry in the series now available on Nintendo Switch in all regions.

Update 1.0.1, which is also the first update ever released for the game, introduces a variety of fixes that are meant to improve the experience. Sadly, patch notes are extremely vague, so we don’t know exactly what has been fixed.