I remember my first experience with dynamic hairs on P5.
I've played with skullcap few weeks and hairs were invisible. I've found by accident that I must select group and changed any parameter for example "hairs lenght" and hairs appears.

Hairdressing was easy with hairdresser windows and hairs properties as "clumpines", "kink strenght" etc. but hairs still were static.
After few months (or years) I noticed dynamic parameters (default position is left bottom of hair room) and button "calculate dynamic". I think that you either can miss this button ;)

If you have ready dynamic hairs downloaded and parented to the figure, on menu bar just click "animation" => "calculate dynamic" => "all hairs"

If you wish to use conforming hairs try to search my posts in another thread where I advised how exchange hairs between figures.

kuroyume0161 - you cannot export dynamic hairs as a prop. It is not a mesch with polys - only edges. Fortunately Kawecki (I love him for it) made python script which can convert them to prop.