What happens to Perk on Item?

You have option to remove some perk from your item with some gems and get chance of having another perks.

I just did that on my gloves and the perk is removed but I didn’t get new one.
What has happened can anyone tell ?

You must forge the skull perk first and spin. After that you gain a perk there. But since you are in cool down, I would wait till cool down is over