Conductivity Curse not activating

I'm encountering a regular issue where conductivity fails to apply. I believe the issue occurs when using another skill before the curse applies the effect to the enemy. I suspect there is a window between mana consumption and curse application that makes the curse vulnerable to being cancelled.

I have recordings showing Conductivity being pressed, weapon swap occurring and mana being consumed however the curse is not applying.

I have picked up as much 'faster curse activation' to the point where I no longer have the ground animation, however, I'm aware the curse still applies. For reliable curse activation I must use it at least twice or wait for the curse icon to show, this feels longer than the 0.7 second cast time the tool tip suggests and makes me vulnerable to attack.

I also feel like mana consumption should occur once the Curse has applied as there's nothing to suggest curses can fail.