[ehPReth]

It used to work, then they broke it in v4 with whatever 'upgrades' they made and haven't brought back the lost functionality yet :/.

You can add /embed on the end to see the singular post without replies, but it's not really a good substitute.

GH issues:

https://github.com/mastodon/mastodon/issues/19953

https://github.com/mastodon/mastodon/issues/23153