Increased duration + Shield charge description

It is never showing increased duration in description of shield charge at right bottom screen.
I am using increased duration gem and shield charge gem. It is needing increasing shield charge stun duration. It is never adding?

It is never working.

Increased duration increases skill effects durations. Stuns are a game mechanic and in simple terms it is based off the percent of monster health you removed. If you are trying to stun with it I recommend the stun gem instead.

Doesn't have the duration tag. Unlikely to affect it even if others did not know.

For convenience, the presence of the duration keyword will allow modification via duration passives and supports. If not, you will need the specific duration passive (Stun Duration) to modify the duration.

increased duration gem is never supporting shield charge gem. increased duration support gem 'D' text icon is never showing in shield charge skill icon. I think increased duration gem is never supporting with shield charge gem.