I sometimes receive Flow notifications along the lines of "Example and 2 others responded on XYZ". Clicking on this notification highlights only the most recent reply, rather than highlighting all replies bundled into the notification. This makes actually following a conversation annoyingly difficult, as I have to remember the how long ago I last looked at the conversation and look through the entire topic for replies with a new time indication.
The same likely happens if one person has posted more than one reply, a notification "Example responded on XYZ" (which is ok) that highlights only the most recent of their replies (which isn't).
I think it used to highlight all replies in the past, making this a regression, although that might just be my memory playing tricks on me. Even in past, though, I recall being annoyed that it jumped to the most recent post even if other highlighted replies are higher on the page.