My friend says that he cannot see furniture with add-ons unless he has vibrant visuals

I’m sorry if I’m wrong but one day my friend joined my world with addons but some are from outside marketplace and when he joined he crashed, I said to him to turn off vibrant visuals cuz I know he uses it then he said he cannot see them and then when he said that he has furniture add-ons in his world installed outside marketplace saying he cannot see it on fancy mode unless he is vibrant visuals mode but i will be sorry if it's fake bug or if it didn't cause by game code but by sommething else please give me guide how to see the new items that are installed outside marketplace with fancy mode