My preference would be to create a new thread/topic for each bug, rather than having a single thread for all bugs. This is the best category for these kinds of topics, though.
Can you describe your issue with more detail?
Are you on a desktop/laptop or a phone/tablet? What OS? What browser? Do you have any extensions installed that may interfere with the site? Have you tried temporarily disabling them or temporarily white-listing bbs.elsewhere.cafe?
Are you replying to a topic (with the blue reply button at the bottom) or to a post (with the grey/white reply button on the post?)
How do you know it’s not shown as a reply? What are you expecting that you’re not seeing?
Are you deleting the post after you’ve posted it, or are you just clearing the draft?
What steps are you going through to rewrite the reply? What is the error message that you’re getting?
Are you editing the post after clicking reply? What error message are you getting in this case?
Feel free to provide screenshots for any of these if you think it will help.
Also, keep in mind that I’m only hosting this software. I do not actively work on the code of Discourse, and I am not a Ruby developer. If we can’t find something on your end that’s causing the issue, I can report it at meta.discourse.org. They’ve been responsive in the past, but I don’t have any influence over how they might prioritize what I report.
Hopefully we can figure something out, but I just wanted to be as transparent as possible.