You are using a Genesis 8 item on a Genesis 3 figure and you probably used auto-fit feature, that's why you lost the item's morphs.
When using a Gen 8 item on a Gen 3 figure you should do this :
_Load the item without fitting it : deselect your figure and load the RH8 hair as this.
_Change the preferred base : select the hair, go to "Edit/Figure/Scene Identification", click the three dots next to "Preferred base" ans choose "Genesis 3/Female".
_Fit the item to your figure : select the hair, right click and "Fit to"... you know the rest.
_Enjoy your G8 item on you G3 figure with all morphs working.
Note : This method works both ways G3>G8 or G8>G3 and for any conforming item such a hairs, clothes, and so on.
OR
You may just use the Genesis 3 version of those hairs (but it's less funny) 😀