Getting instantly kicked out of certain villagers' trading GUI on minecarft server.

While playing on my private minecraft 1.14.3 server with my friend, he noticed that when he attempted to access some of the villagers' trading GUIs he instantly got kicked out. When I came to check it out I also experienced the same bug. We are not sure if it had something to do with the server software as we are playing on a slightly modified server.