bug? - Red Weaver DR in Battle for Eveningstar

[Xanom]

Fighting the Weaver in Battle for Eveningstar (Epic Hard). Noticed I was getting yellow numbers: combat log reports DR/good.

Cast Planar Weapons (good) - Artificer level 20. Icon for Planar Weapons (Good) appears. Sword reports that it now bypasses Good DR.

However, Red Weaver still applies DR.

There's obviously a bug here, but I don't know whether it's with Planar Weapons or the Red Weaver.

[dredre9987]

Fighting the Weaver in Battle for Eveningstar (Epic Hard). Noticed I was getting yellow numbers: combat log reports DR/good.

Cast Planar Weapons (good) - Artificer level 20. Icon for Planar Weapons (Good) appears. Sword reports that it now bypasses Good DR.

However, Red Weaver still applies DR.

There's obviously a bug here, but I don't know whether it's with Planar Weapons or the Red Weaver.

Its DR is 12/Good on normal according to the wiki. Just to check you aren't using any other item enhancement on your weapon besides planar? No deadly or elemental weapons or enchant weapons?