For better help, provide your ‘snapshot ID,’ which copies everything about your character and settings so we can duplicate your exact scenario. To get the snapshot ID, click the green HELP link next to the big “Best in Bags” etc section headers. Choose ‘create support post.’ A window pops up with a Snapshot ID. Share that ID in this post. Feel free to delete this help text when making your post.
We will post a fix for this soon, sorry about that. The problem is that you have the DISC belt in your inventory, but set to the tanking version of the item - which we never considered for a priest. You could probably get around the problem for now by changing the belt to a different version.