No it is disabled as I want to choose them manually and also register them in the lexicon. I also double checked the option and it is disabled. I bought 3 times 10 items at Shataku and just the purple one disappeared. I was able to register it at the Lexicon, but it was not in my inventory.
I also have the same issues with the accessiore shop, where I buy items and they do not appear in my inventory. Also, I had a chat with some people on the server who had the same problem as me.