I wonder if language is a factor in this at all? I know mathematics is written entirely in English but most likely discussions still happen in local languages. Could part of the proof be lost in translation?
https://en.wikipedia.org/wiki/Shinichi_Mochizuki
About Hoshi, I have seen him in a conference video before, and have an impression that he isn't good at English, which can make a bit difficult in discussion.
I don't know about Scholze and Stix.