Chance to cast on striking

[Raven Vale]

Hi folks , OOLM or Out of lurk mode for a quick question , think I have only posted once since the original forum , but hey , better late than never . I have taken a 2 and 1/2 year break from D2 and decided to come back to try the new and improved 1.10 . Ok question is this , I made a WW sword barb and had found flamebellow Unique sword , this sword has a 12% to cast level 16 firestorm on Striking . Now I used this for some hours yesterday and this thing never went off once in WW , I was getting the effect quite easy when standing fighting but never in my crazy death spin , I was hoping to get a pair of similar swords with different effects just for a laugh when WW'ing . So do these features not work in WW for every weapon with a % to cast on striking / just flamebellow / or is it bugged . Any help would be appreciated .

Take care