Per my own experience, the economy v2 api from client side to purchase inventory items via
PlayFabEconomyAPI.PurchaseInventoryItems does not require a the entity (of type EntityKey) field to be provided from the Unity SDK, and it worked for quite awhile for us, but at some point it no longer works and results in 400 error with error detail saying nothing. Digging it out and realized we'd need to provide the entity key assembled from
PlayFabSettings.staticPlayer.EntityType to make it go through.
I thought if the entity field isn't provided, the caller entity is filled in automatically. Is what's mentioned above a new behaviour?