I don’t think it was meant to show up the way it did for you. I too sometimes see replies (mostly my own, but sometimes from other users) as a top level post but then refreshing the feed shows them at the correct level.
Discussion
Yes we need a lot of work on the feed in general.
The default algo will ideally show a mix of levels of conversation without repeating the same threads over and over.
Settings will be available to not see replies, or set depth you want to see replies to be considered.