Filthy Crone VFX not visible

I've died a number of times to random spike damage I didn't see coming and have been confused. Today I happened to notice a small purple particle emitter at my feet just as it happened, and started paying attention to the purple (specifically purple for some reason) filthy crone attack and found that yes. The purple attack sometimes does not appear in its full animation. I'm currently assuming it's under uneven ground or something? Either way, it's showing the VFX, but only the little barely-visible purple particles at the center, I'm not seeing any sign of the spell circle that's supposed to come with it.

There are times where the full purple spell circle is visible as expected, and other times where it is not. I've notice no pattern to this.

Bug Report ID sent some 5-10 seconds after I died to this attack and respawned:
3,278,957,155