@gat0 Yes, thank you for reporting this. I just confirmed that the anthy input method is broken on Endless OS 3.1. It is working on my development laptop, so I expect we will be able to fix it for the upcoming 3.2 release. For what its worth, anthy is a phonetic input method, which works by typing the English/Latin characters that sound like the Japanese word.
So, for instance, when it is working, typing "konnichiha" yields the following Japanese characters: "こんいちは", which I think is correct, though I don't speak Japanese.
Hopefully the kana or macintosh keyboard layout will help in the meantime, and do let us know if you have any problems with anthy after we release version 3.2.