Dominator set #5 bonus only triggering with 2h weapon

[kmark101]

As the subject says.

On my IB, the Dominator set #5 bonus (10% chance to Taunt on hit) only triggers when I use 2h weapon. With 1h weapon + shield, it never triggers.

[anarchypark]

bugs go to bugtracker.
how many times did you swing?
at least 100 for evidence.
better to same target but condition is hard for testing, 1day long test in SC/orvr would be enough evidence.