Hi,

Preamble:
The skill's description says "+1% Bonus Damage to DoT effects for every point of their respective resistances". After some discussion with several English Mayors (Discord chat) we have come to the conclusion that 'their' in this case refers to "the DoT effects", meaning for every point of an elemental resistance the player has, the player should gain 1% bonus damage in the dot of the same element type (disregarding resistances to "all").

For my character that would be these values:

The expected result:
The passive should, according to the preamble, give exactly the same numbers as bonus to their respective DoT damages.
So 14% Bleed and Poison, 26% Burn, and 30% to a hypothetical warp based DoT.

The observed result:

I have verified this behavior is unrelated to equipped gear, and appears for other players as well.

I'd like to add how it's interesting that the value isn't 0, but 1. Otherwise this bug would've been really hard to spot as a player.