You have to explicitly set the language of your reply to English, I find. Since you can't on most apps, you may just be unable to reply from them.
You are definitely seen by kbin.social: https://kbin.social/m/lemmy@lemmy.ml/active has your post. Why do you say you can't reply? Sometimes the synchronizing has some hiccups.
You can see how kbin.social is "seeing" you here: https://kbin.social/u/@pfannkuchen_gesicht@lemmy.one
because the apps I use literally say I can't post a reply. Or in case of lemmy connect it just doesn't do anything.