https://wccftech.com/super-mario-maker-2-uploadable-courses-limit-increase/

Super Mario Maker 2 recently released a tweak in its online functionality that will make all avid course creators happy.

Earlier today, an in-game notification confirmed that the total number of uploadable courses has been doubled, going from 32 to 64 total courses. The notification also informed players that this limit will be increased one more time at a later time.