Guild Wars 2

So I’ve been playing around with a build that utilizes sigil of intelligence due to my lack of precision but it isn’t working half the time.

I am certain of this as I switch weapons in stealth so any additional damage I do would reveal me.

Any explanations?

It may be on cooldown if another sigil had proced before hand. Could be wrong although it seems that they all share an internal cooldown.

I know that when if I try to swap to say gemoancy and battle only the battle sigil procs. And if I swap soon after a fireblast then neither proc.