Hmm poking about the internet - player state feels like the best place for the inv to go.
But to some extent the blueprint which contains the Inv component is irrelevant. The updates need to be done server side. SO… how do you get your GUI to pull from the server side component ?
Or do you mean, updates occur on the server only, but the data object is replicated - so the client receives a copy of that data via replication ? If so… this is where I came in. My inventory is an array of uObjects and uObjects DON’T replicate.