Further testing is suggesting that the barrels are a red herring, and something else is causing the hammers to disappear. See my reply below for further updates.
original post
Hammer Throw projectiles disappear (as if colliding with a wall) when they hit the spot where a barrel used to be, even after that barrel is broken.
This video is taken immediately after completing an arena wave. The hammers worked fine for the duration of the wave, but as soon as I broke my reward barrels, they started exhibiting the behavior shown. The spots they’re disappearing are where reward barrels used to be, before I broke them.
I then move to a different spot in the arena to show that they work fine in other places (where there were never any barrels), and back to the center (where they show the bugged behavior again).
This issue gets temporarily corrected every time the Arena zone gets reloaded, but since there isn’t a zone transition between every set of 5 waves, it can make Hammer Throw feel really bad in Arena - having all your projectiles disappear if you fight in the center is pretty rough.
Further testing reveals it’s not about the barrels: something is causing invisible collision zones to appear sometimes, but I haven’t figured out what it is yet. Once such a zone exists, Hammer Throw projectiles will disappear upon entering it, and if the skill is used from inside the collision zone, the skill will barely work at all.
Here’s a video of me moving around a small area and using Hammer Throw to figure out by trial and error exactly where the collision bug zone is. As the video goes on, you can see it becoming increasingly clear where exactly the no-go zone is for my hammers (indicated with my cursor once I figure it out).
I’m not certain what the trigger is for these zones to appear. It’s vaguely seemed to me that they’re more likely to appear:
In places where I’ve destroyed breakables or killed enemies (but there aren’t any in the Echo of a World zone)
If I hit the hotkey for Hammer Throw while I’m still holding down left click to move
Shortly after my Ring of Shields deploys
However, none of those consistently triggers the bug.