The begin play code has been reworked, You will need to create 2 new custom events one set to run on client with reliable ticked and one to run on server with reliable ticked.

Then copy the image below Add the highlighted nodes show in all the images below you will need to create the custom events Server Construct Inventory and Client Loaded Save.

Add the highlighted nodes show in all the images below

Any where in the add item and remove item in the storage component that is using the inventory output pin of an item variable needs to instead use a self node, all the locations are shown in the images below