Gaussian IO 'Chance for Build-up' not firing when slotted into Toggles

[Ozryk]

I have https://paragonwiki.com/wiki/Gaussian%27s_Synchronized_Fire-Control 6-slotted into Tactics on my character, but I never see the IO build-up proc trigger. It should proc an average of once per minute.

[Adeon Hawkwood]

I can confirm that it works in Targeting Drone which is also a toggle. I can't recall specifically testing it in Tactics but it should work there as well.

[Zep]

I have it in Tactics on a controller and it does fire. Maybe 1-2/minute - the icon only shows for about 5 seconds so you really have to look for it.

[knightowl - Pinnacle serve]

Does it appear in the 'Hit Rolls' chat tab as an autohit power when it procs?