Transmog issue on frostmourne season

[Babord]

I'm playing on blackrock but frostmourne season.

I've tried to transmog items with scrolls but when using a scroll on the item i get a red text: "Item is locked".
The item I'm using the scroll on is bought via transmog vendor.

I dont get this issue on other servers. I havn't tried on blackrock but icecrown bracket.
Guessing this tmog feature is disabled for blackrock players which are on frostmourne seasonal

[skullatbash]

when using a scroll on the item i get a red text: "Item is locked".

what is the item's name?

[Babord]

No items work but to give an example: "Gladiator's Gavel".
I click on Scroll of Deception, cursor turns on blue outline, and then click on Gladiator's Gavel --> "Item is locked." and blue outline disappear.

Edit: I just tested it on Blackrock but Icecrown bracket and it worked perfectly fine.