Earth shatter of fragility.

Does Earth shatter of fragility have an invisible reduced skill effect duration cap? The reduced duration wheel along with the less duration do nothing to it. At the moment I have less duration support linked to it but when combined with the tree passives it does nothing. I took off the passive points and its still the same duration despite what the tool tip says.
When I unsocket the less duration support the spikes do take longer to detonate however i have not tried it vice versa because I ran out of regret orbs.