Brownie, gook, and nip
In particular, the Quanta Magazine says that Jakob Stix and (the young, celebrated, fresh Fields Medal winner) Peter Scholze claim that they have isolated an unbridgeable gap in the Japanese proof. They met with Močizuki. The two sides couldn't agree. Scholze was just a "cheeky Hun who just barely jumped out of a vagina", Močizuki was a "brownie, gook, and nip", you can imagine that the exchanges between mathematicians keep their highest standards of diplomacy.