Have the 500 Bountiful Delve achievement. Golden Coffer Key is listed as the unlock but can’t transmog it nor the Silver one.
I encountered the same issue. I had completed the achievement before the patch and it did not retroactively grant me the Golden Coffer Key transmog.
Still an issue after today’s reset.
Also got the achieve before patch…can’t use the transmogg
Ditto. Had the achievement (The Key to Madness) before 11.1, did not receive either cosmetic rewards.
Got my cosmetics in the mail now for anyone else who had the issue!