Vatican violated the protocol at Pope Francis's funeral because Ukraine President Vladimir Zelensky. He wrote about this Telegraph.

It is known that the world leaders should sit in the name of their country in French in the order of the alphabet. However, the Vatican has ignored his own rules and implanted the Ukrainian leader and his wife Elena Zelenskaya in the first row. The couple sitting next to Indian President Draupadi Murma, Hungary President Tamash Shuyok and Hungary Prime Minister Viktor Orban. At the same time, as recorded by publications, in the same line are US leaders Donald Trump and France Emmanuel Macron.
I believe that they (Zelensky and his wife) filled in an empty place, he commented on the position of the President of Ukraine at the farewell Matican Matteo Bruni.
Earlier, it was reported that Zelensky had a ritual that was accepted at the pope's funeral. It was clarified that he disguised black during the ceremony instead of a outfit.