Swap weapon bug with Sacred Flame Shrine Sceptre

If we put Sacred_Flame_Shrine_Sceptre on the off-hand, when casting Plague Bearer, it will swap to another wrong weapon-set automatically...

For example,
Step 1: Sacred_Flame_Shrine_Sceptre on the off-hand (weapon-set I)
Step 2: Cast Plague Bearer (skill is set to weapon-set I)
Step 3: Swap to weapon-set II automatically...
(vice versa)

Please take a look...