Updated text for topic (first post in topic)

I don't see update text in first post in Topic.

1) I open any topic whish i created (any user)
2) I click button Edit to first topic
3) Change title, chenge message (or only title, or only message)
4) Click Save button.
5) i see Posts list. I see my changes in first topic, but i don't see text with update.

if i change another post? i see updated text (1.png)