When I comment on a post in a thread, the comment (naturally) ends up at the end of the thread,
But it should be possible to click on something that returns you to viewing the post you've replied to, so that you can carry on reading the thread from where you were. It's easy on DPR.
Don
I have a touchscreen on this laptop, so I just swipe the screen left-to-right. The browser's back button should return you to the right place, too.
One web forum I use puts your reply directly below the post that you replied to, until you leave the page. That is a nice behavior.