The save system is setup to save the players guilds (Including its roles, members, settings and name) Groups (Members and leader). Both of these are saved on the server/host of the game. They will be loaded when a player connects to the game and assigns the players guild and group.
The save system also save the player chat layout (This includes chat settings and layout and social settings). These are saved on the client so each client has there own save for these settings on their PC.
When testing in editor remember that all clients are using the same game files, this includes there chat layout and social settings save. So when you play and load a save all the players will have the same chat layout as they all load from the same save. THIS WILL NOT HAPPEN IN A PACKAGED GAME. When players play using a packaged game on their own pcs they have there own chat layout and social settings save.
When testing your game you may want to delete the Chat Groups Guilds save, this can be done with the BP_SaveHelper, you can place it in your level and with it select in the details panel there is a button that says Delete CGG Save this will delete all the saves.