Getting an error "You are almost out of storage space! Minecraft has restricted access to this feature until you clear up additional storage space" in Bedrock when I try to load my world (the world itself is only 12.8MB)

Yet my Xbox has over 900MB free on the HDD

I have cleared the cache in the game (under settings, storage) - there was only 0.78MB in the cache items. Other items in the storage  - World items total 182.3MB, Resource items 95.6MB

Any ideas?