Some patches ago, backpacks for characters digging in the inventory, that weren't ESO+, were disabled.
As of the last 2 pc patchs, people noticed backpacks in world looking empty but weren't.
This most recent Xbox patch, everyone has backpacks again (plain for scrubs, fancy for +)
I'd be better able to give you a timeline but since I'm second class on console, and there have been so many patches, I can't be arsed. But I wonder if these things are related?
Xbox NA/EU
"Once I misplaced an entire roast chicken, so this doesn't surprise me."