Avidity (Deadeye ascendancy) Frenzy charge gain bugged?

Most of the times when i place my ballistas while moving i do not generate any frenzy charges with Avidity when i keep moving (without using any other skill) until i spam my move button. (i generally hold my move button at all times even when placing ballistas)

Edit: just saw it took something like 5 sec to start generating frenzy charges when i stopped using any skill and just kept walking.