Scorched Ground Elderich Boot Mod Doesn't Work in ToA Arena

The elderich boot mod Drop scorched ground while moving lasting 2 seconds doesn't work in the ToA arena. I can run around a mob while hovering over their nameplate to see that they never receive the scorch debuff. I can see they aren't ailment immune because they are affected by the shock from my tempest shield which I can see as a 9% shock when I hover the nameplate.

+1 I also see this happening.

Actually, tipped off by another post about Brittle Ground mod, I tried going back to hideout and now I drop scorched ground correctly again. It seems to turn off after you die once and it doesn't come back until you leave Halls of the Dead.