In first 3 pictures you can see it working locally. When your inventory is almost full and you pick up only 2 pieces, the widget changes from 5 → 3. This can’t be seen by other clients. Problem is only with widget. The actuall amount there is I have already figured out and seems to work.
My atempt to replicate widget is this… But I’m always getting “accessed none trying to read Pop Up Ref” in ThirdPersonCharacter.
Widgets are created locally and therefore other clients will have a different widget reference which is most likey why you get the null reference. Do you set the Widget reference only once?
Otherwise the issue is with the MasterPickupActor specifically or you are not setting the replicated variables on the Server.