Content is hidden due to not choosing the languages in the settings.
Making the language settings opted in by default should solve this initial struggle, opting out should be done manually. Putting check boxes next to the languages on there for selection should make things easier too.
This has been an issue long before the guy in the linked post reported it. ~~I've had to face this same issue on other instances as well so it's obviously a Lemmy issue and not instance specific.~~
Please understand that these sorts of small but very visible troubles are what keep people away from this platform. You sign up and go to any community only to see no posts or only those not tagged with a language (You could even miss those if you don't choose "Undetermined"). Any new user would be confused "Are there no user at all?" "Is this community banned?" "Is this instance defederated?" Each of these doubts would just push any new users out.
Edit: This PSA was over 9 months ago now.
Edit 2: It seems to be instance specific, lemmy.world and lemm.ee both have this issue as far as I've seen.
Edit 3: Thank you everyone for your help.
I see now, if an instance has any site languages configured those will be applied for new users. You can see it in
/api/v3/sitefielddiscussion_languages. However both lemmy.world and lemm.ee return all languages there.Edit: Im removing this as part of the PR to set new user languages from accept-language header, it doesnt make sense anymore with that.
I tried testing with a new account on ds9.lemmy.ml aswell and it seems to be working well. Tried 2 different languages and both showed up correctly without touching anything in the settings,
^This is a good idea.
Also from the settings "Warning: If you deselect Undetermined, you will not see most content." comes off as if you need to select it to view things while it's actually a language filter to only show the selected languages only. Renaming it from "Languages" to "Languages filter" and rewording the warning may help further.