since the last 2 oracle coming i try to activate a pet, it doesnt' work.. but now i give her the item and see the pet i try was active.. so, activate is working, but the button no show it..

Does it show the correct pet active on Kumos for you now by chance? I think it might be slow to update on Kumos -- I made a different pet active on Kumos and nothing on the page changed even after refreshing (to show the pet as active). It DID immediately update on Legacy, though (from the Kumos update).