Risa kit 20% chance for summer kit module to trigger bonus effect only works 5% or less

The Risa kit has the following bonus effect for Risa kit modules:
"Whenever you activate a Summer Kit Module: 20% chance: Activate any Summer Kit Module at random"

My Risa kit has 4 Risa modules (Graviton Spike, Corrosive Grenade, Ball of Lightning, Floor is Lava). The first 3 of those I tend to trigger continuously due to lower cooldowns, and save the lava one. Yet despite triggering them often, especially the first 2, I rarely see the bonus risa module effect. I'm lucky to see it 1 time in 20.

For example, on Tuesday I went to Kobali Prime and did back to back the 2 missions: “Breaking the Wall” and “With Our Last Breath”, which represents about 15-20 minutes of constantly using multiple kit modules, yet in that time I only had 1 risa bonus effect trigger, despite probably using risa modules 50+ times. And it was not due to not having an enemy targeted when use my module....that just causes the bonus effect (like lava, etc) to center on me instead of a target.

Others I have spoken with have seen similar low results...too low to just be accounted for by bad luck RNG. Is the the tooltip wrong and kit was intended to trigger these far less, like 5%?