Hello, we have noticed the same bug on Ubuntu's side: https://bugs.launchpad.net/ubuntu/+source/mozc/+bug/2121938
I proposed a fix that is waiting for a merge : https://code.launchpad.net/~vhaudiquet/ubuntu/+source/mozc/+git/mozc/+merge/492191 I can draft a pull request on Debian Salsa Gitlab if you want :) but I my account is waiting for administrator activation
