Windows 10 Why does my refresh rate show 60.01 Hz instead of 60 Hz?

This is completely normal and nothing to worry about.

Monitor refresh rates aren't actually exact whole numbers most of the time. What we call "60 Hz" is often really something like 59.94 Hz or 60.00x Hz, depending on how the timing is generated. Windows (and your GPU driver) will sometimes report the precise calculated value rather than rounding it to a clean 60.