Tempo Track. Smooth Tempo function

Hi guys!

I`m trying to use “smooth tempo” function after tempo detection but the button is grey (innactive).
Can somebody tell me what am I missing?

I’m finding that too, I don’t know how to make the button active. All the other ones are, except Smooth Tempo and Multiply by 2.

Did you figure it out or does anyone else know why they are greyed out?