I had the same problem initially when joining Lemmy, but it works now.

To comment I had to use the web interface, and where it says "select language" choose English. Otherwise you're posting with "no language" , which is not on the Community list of language, so the webUI would spin endlessly, and Jerboa would fail with language_not_allowed.

I think if you choose English once when commenting from the web interface, Lemmy should remember it and Jerboa should use English and should work. Assuming you don't need to often swap between languages.

I think the language mechanism is probably a good thing in the long run, but right now it feels a bit janky and confusing. For sure Jerboa needs an update to be able to choose Language in the app itself. It also needs to not eat your comment when it fails, cause having to type out a long comment again is infuriating.

For some more info, see: https://reddthat.com/post/1976