What would cause my brand new serpentine belt to slip off shortly after driving?

A new serpentine belt may slip off shortly after installation due to improper tension, misalignment of pulleys, or debris caught in the belt or pulleys. Additionally, worn or damaged pulleys, a failing tensioner, or incorrect belt routing can contribute to the issue. It's important to ensure that the belt is properly installed and that all components are in good condition to prevent slippage. Regular inspection and maintenance can help avoid such problems.