Adafruit motor hat library examples not working

According to the Waveshare JetBot WiKi, you need to use their code since the driver is different for their version of the JetBot:
https://www.waveshare.com/wiki/JetBot_AI_Kit

This might help as well:
https://forums.developer.nvidia.com/t/jetbot-motors-are-not-moving/75607/20