Wow, ok, it seems Hacker News rewrote my submission link to use old.reddit.com which doesn’t support the sharing link format given by the Reddit app? I’m sure I submitted https://www.reddit.com/r/midjourney/s/hZgOecxVcK
Edit: yes, exactly, I think what happened is they are replacing "reddit.com" with "old.reddit.com" before following any redirects. On old.reddit.com the link format I submitted is shorthand for "submission", and because the link processor is not logged in, gets redirected to the login page (and finally the URI parameter that would indicate where it came from gets cut off). Ok, next time I will stick to the traditional reddit links here :)
[added after closure so in place of a comment]
I think old.reddit does support such links, I have a "old.reddit redirect" browser addon, and then your link below takes me to https://old.reddit.com/r/midjourney/comments/1bgdk0c/whats_a... -- perhaps that won't get rewritten?