I have been trying to barter with Piglins recently, and I have bartered with them multiple times, and every time I did it, I have only gotten Nether Wart blocks. This has been a problem for me since the first beta released for the Nether Update. I have tried to barter with different Piglins, though I still got the same item. I made multiple worlds to see if it happened there too, and even on different worlds, Piglins kept giving me the same item. This has happened to one of my friends as well, where they said they kept getting obsidian and nothing else, no matter what Piglin they bartered with.