OT: Ping Agent Users

My Agent newsreader has developed an annoying trait which I cannot
seem to find a setting to correct. The screenshot below shows how it's
displaying messages. They *should* all be nested under the original
subject title, but they're all expanded which is making it really
difficult to follow who's posted when:

https://disk.yandex.com/i/7gqKvLkrz4NRlQ

Anyone know where the setting for this is, please?

Thanks,

CD.