I purchased the following cosmetic sets from Osidion in Dornagal: Lilac Educator’s Knowledge, Midnight Educator’s Knowledge. Each set includes two chest appearances: a Robe and a Vest.
I received the Robe appearance for each set, but not the Vest appearance. The Vest appearances are still marked as unknown for my collection.
I submitted a ticket to customer support about this issue, and they suggested a UI reset which did not resolve the issue.
Anyone else experiencing this?
I have been having the same issue with a few sets like that, the preview will show a vest options, but when you go to transmog it like that it will be a robe instead. The Delver’s Cloth Armor is another one that has this same problem.
I just logged in today and the issue seems to have resolved itself. The vest appearances are now in my collection and I can mog them. I haven’t done anything or changed anything since my OP. 
Perhaps come back tomorrow and see if it’s resolved, or put in a ticket?
This bug might have cropped up again since I do not have the Cobalt Educator’s Vest despite purchasing and using Cobalt Educator’s Knowledge.
I’m gonna see if the weekly reset tomorrow fixes it but logging out and back in, as well as fully exiting the game, does not unlock the vest transmog at this point in time.
Waited for reset, weekly and daily, and it looks like this bug is a bug again.
Still do not have the vest sadly 
Have the same bug. 4 different sets are not giving the vest appearance after multiple logins and the weekly reset.
Midnight Educator’s Knowledge
Cobalt Educator’s Knowledge
Leafy Educator’s Knowledge
Lilac Educator’s Knowledge
All 4 of these sets are bugged out and not giving the vest mog as they should be.
Yeah I didn’t purchase anyone other ensembles after I realized the Cobalt one was bugged. But I guess that’s confirmation now that it’s effecting all the ensembles now, not just one.
I wish there was a way to let people know to hold off on purchasing them right now but as it stands they will probably have the same issue and find this thread after the fact lol
Bumping as it’s still a bug
Bumping since the newest patch 11.1.7 still hasn’t fixed this it seems
Checked today and over a month after my last post these 4 ensembles are still bugged and not awarding the vest appearances.
This is still an issue.
Still an issue +1
Another week, still an issue. Appearances not being awarded correctly for the following.
Midnight Educator’s Knowledge
Cobalt Educator’s Knowledge
Leafy Educator’s Knowledge
Lilac Educator’s Knowledge
Bumping as this is still unresolved and support has falsely claimed that this isn’t an issue.
Just ran into this and even accidentally wasted an Earth-Encrusted Gem on one of them, because they’re listed as not being known, due to learning 8/9 pieces.
I have run into this bug as well. I purchased the Leafy Educator’s Knowledge and did not receive the Leafy Educator’s Vest. I do have the vests from a prior purchase of Midnight Educator’s Knowledge, before this bug came into existence. Relogging did nothing.
Still an issue in 11.2. I just bought all the sets and didn’t receive the Midnight Educator’s Vest, Leafy Educator’s Vest, and Cardinal Educator’s Vest.
Adding my voice here as well. Missing a vest from one of the ensembles and GM support couldn’t assist. “This needs to be addressed by our developers.”
Blizzard please fix these minor bugs as well as the major ones. They are chipping away at my enjoyment of the game and I am sure I am not the only one.
Bumping as well as of August 15th. Still bugged and it has not given me the vest options.
Unfortunately this appears to be something Blizzard likely would never give the time of day, it’s simply too minor of an issue.
I opened 2 tickets for this and still nothing. One of the GMs threatened to give me a ban for abusing the ticketing system for reopening the ticket.