The problems with the new comment section haven't been fixed, and now you're creating new major problems.
My suggestion is to revert to the last comments format that wasn't a hot mess, the one from about 2014.
I get same behavior in two different browsers. First, for a long time already, if you vote on the first response to a comment, the forum crashes, this is shocking incompetence. Second, having never addressed your shocking incompetence, you doubled down on it. Now, every vote on a response collapses the whole table of responses.
But the shockingly incompetent programming is only the lipstick on the shockingly thoughtless pig that is the new comment section design. You can hardly read your own comment as you type because the box is so small. If you want to review your comments, they are not reliable linked to the original article, but that's OK, because if you responded to someone else's comment, it won't show you the original thread anyway.
Please pull your heads out and fix these issues ASAP.
