Sienna's new staff and its "DoT"

I am unsure if this is an actual feature (would kinda make sense if it were), but does Sienna’s new staff AOE DoT Stay on targets after they leave the geyser or does it only tick when they are inside the flames? The first day the new weapons came out the staff was performing excellently and flames seemed to keep the DoT outside the geyser.

But now, I am noticing that the DoT stops ticking after they leave, not using Lingering Flames at the moment. Will be testing out if the DoT persists with the talent or not.

But yeah… is it intended or not?

Pretty sure it’s just like any other DoT, in it will ignite an enemy for so long as it ticks for, unless, as you said, you are running lingering flame.