Hello @toffifee
your code works for me using an M5AtomS3 (non R).
That said, M5AtomS3 uses a different IMU chip (MPU68860) than M5AtomS3R (BMI270 / BMM150). So my best guess would be that UIFlow2 is not fully adapted to M5AtomS3R (yet).
@hacxx : FYI @toffifee is using UIFlow2 - there is no Imu.begin().
Thanks
Felix