Hunter traps dont do anything if placed too close to walls.

[Cabro]

Mostly checked with Frost/Freeze Traps, not with the fire ones. If you place traps too close to walls (corners especially), they will trigger but not apply their effect. LE: I think it's the case where they would trigger due to proximity, but there is no los trap-target.

[Zarant]

I did some testing, and it appears that whenever a hostile unit triggers the trap and the hunter is out of LoS of that trap, the trigger animation will play out but nothing will happen, I can reproduce that with both frost trap and explosive trap, freezing/immolate trap seem to work even when i'm hiding out of LoS.