I didn't need to log in: I got the rest of the thread by following the link "see rest of this thread". That link though is easy to miss, what with being somewhere mid-page and being surrounded by elements that are visually much louder, and I, too, wish that no one here would submit or upvote links to Twitter.

Twitter seems to be doing some kind of A/B testing. Clicking the "See rest of this thread", pops up a login window, which on being closed takes you back to the initial page.

Yes, but we all know where this inevitably goes. See Instagram, Reddit, Facebook, Pinterest, etc

I was seeing that a day ago too, and it's gone now. They're definitely testing something, and it's garbage.

I had this issue, sussed it in about 10 min. If you're in a Chrome-based browser (incl Brave), DL the Ublock Origin extension, then: Extension options > "My Filters" > add one of the filters in the reddit thread linked. (https://www.reddit.com/r/uBlockOrigin/comments/p5lgcv/twitte...)

I did find the link, but was blocked by a login popup. It must be an A/B test.

Someone posted a third-party thread-unroll link elsewhere in the discussion, I don't think that required a login?

Ah, thank you that makes more sense.