i remember for other classes as long as you are in that spec, you can tmog the artifact appearance regardless of the weapon type compatibility (i think i did this for my lock in 8.3 from duel wield to double handed).
And today i found out that i cannot do the same for my frost mage which has duel wield weapons and wants to tmog into double handed frost artifact staff.
Is this a new bug or what we had previously was actually a bug?
Wait, wut?
You’re saying you want to effectively dual-wield staves, or at least look like it?
Or have like staff in main hand, something else in off hand?
Because I don’t think either of these scenarios were ever possible, unless I’ve missed something.
sry clarification:
i want my character to just show the double handed staff
So effectively, your Frost Mage has a 1h weapon equipped in main hand and an offhand equipped in the offhand slot and you want to use the Artifact staff appearance?
If that is correct, then you should be able to use the Legion Artifact option in the dropdown menu when you have your main hand weapon selected.
Please note, that by choosing that option you will be restricted to only using your current spec’s Artifact appearance.
Yup, this 
yeah exactly what i am hoping to do.
i also remember i did it for my lock a while ago and thinking “man this is a good feature they have”.
but now the option is just gone for my character. when i go to the artifact dropdown menu for main hand tmog, it’s just empty.
Once I can actually get back in the game I will check on my Frost Mage.
/taps fingers while waiting ever so impatiently …
Servers are up… you at work or some region beside NA?
Oh no, I’ve been on for about 2 hours (they actually came up a few minutes early) – but switching servers has been having problems for me.
But I finally got through to my Mage’s server now.
Okay, so this is not what you are seeing when you check on your Mage?
The above image was taken with my Mage in Frost spec.
This is good to emphasize.
Make sure you’re actually in frost spec lol
Sometimes these problems are as dumb as that.
The below image is of my Mage in Arcane spec. 
The below image is of my Mage in Fire spec.
For all three of the screenshots shown, my Mage equipped a 1h sword and an offhand book for testing purposes. She normally has a staff equipped.
yeah mine is empty for this page.
i wonder if it’s because i am using the ward (the pvp one)?
i bought a sword and it’s showing the tmog for me, but not the ward
unfortunately i have to stick with this ward for a while 
Can you link your Mage so I can see what they have equipped?
sry just saw your reply.
my character’s website (wodden-sargeras) is not updated somehow, but the main hand is Crimson Gladiator’s Wand and my offhand is the drakebreak’s horn (i cannot post a link it seems)