Under the following conditions, ALL critical-hit sigils are rendered completely nonfunctional on a two-handed weapon:
Character has a two-handed weapon in one weapon set and two one-handed weapons for other weapon set
All three equipped weapons have the same crit-hit sigil. It might also be true for if only one of the one-handed weapons has the same sigil as the two-handed weapon, but I didn’t consistently get the bug for this scenario (whereas the bug is consistent if all three weapons have the same sigil).
Bug testing notes:
Tested using superior sigils in sPvP and PvE. Not tested using sigils of generosity, strength, purity, nullification, or water (but tested with all other sigils). Not tested using major or minor sigils.
True for multiple professions (tested with both guardian and mesmer) and on two accounts.
Doesn’t matter which types of two-handed and one-handed weapons are equipped (e.g. greatsword, staff, wand, sword, etc., they all exhibit the bug)
The sigils do work if each entire set has different crit-hit sigils—e.g. a greatsword w/ sigil of blood, then a wand and focus both with sigils of air.
I’m unsure if either of the two one-handed weapon sigils becomes nonfunctional, but I don’t think they do.
Maybe the bug is due to some glitkitteneeping track of the cooldown time for the sigil?