I’ve been noticing this behavior quite often and it’s a bit annoying, to say the least.
Sometimes some emails are sent to the Junk folder, I have no idea why…
For example, today I received a notification from the Discourse forum and it went to Junk, even though I always receive those notifications in my Inbox.
So, I went to the Junk folder, and manually moved that email to my Inbox, but it was sent to the Archive right away.

I noticed, in the past, that this also happens when I right click and choose Move to Inbox

Why is this happening? Can I disable the archive completely? Why is this even there and what is the purpose? If I want to archive emails, I can create my own mailbox for it.