Ages ago (like, many years) I encountered an issue with my fae monk character. Whenever I would try to preview weapons, etc the dressing room window would open, but the weapons would not be displayed as 'unsheathed' the way they're supposed to. In order to see the weapon unsheathed, I found I had to first click 'clear' and then preview the weapon again. Or, 'clear' & then 'unsheathe', then 'reset' and preview the weapon again (ie, the former showed it with my toon naked, the latter with his gear/armor on). This year, I finally figured it out - the Circlet of Love & Circlet of Valor from the Shard of Love appear to be the culprits. I'd been wearing the Circlet of Love on my fae monk for a long time and this year I added the Circlet of Valor to a couple of my alts. Low and behold, the same problem started happening with them. I found that if I unequipped the circlets, weapon/shield previews in the dressing room work normally, but if it is equipped, they don't. A bit of an odd bug, and entirely cosmetic, but all bugs are worth reporting.
I don't have either of these items, but a couple of my toons (the fae and the ratonga, iirc) have much the same problem, where weapons won't display in "active" mode. Could be related?
It could be I suppose. I know that one of the three characters I've got these items on now is fae. The other two are kerra.
This was a weird one. For some reason we were checking if the equipment had a mesh when going to the dressing room, so those particle effect cosmetics (that don't have meshes) were causing it to forgo the stance update. Should hopefully be fixed in the next update. Thanks for reporting!