Does that mean it applies to the end users of the NodeBB forums?
theme ver : latest
nodebb ver :
category config /Recent Replies setting
but... it showing one sub in category page~
how can solve it???
This is an intentional design choice.
If you really want to display more replies, remove line 30 and line 45 from this file.
The recent replies are stored in the db, so it won't show six unless there are six new posts after you change the setting.
You will also have to do some custom CSS so that it doesn't look dumb. Like above. Give
[component="category/posts"] a height of 45px for example.
It also looks like you may have deleted all of that section, only line 30 and 45 need to be removed.