When I optimize, AMR uses this chest for Fury and a different one for Prot. When I go to Prot upgrade finder, it lists this chest for Prot and tells me that I already own it.
When i force lock it on optimizer, it shows it as a downgrade.
I would guess this is because your priorities on the left hand side of Best in Bags. Drag and drop them in the order you play to get desired results.
AMR will not pick gear that requires to re-gem/re-enchant/re-set azerite that’s already taken by a higher priority spec.