Question Menu [home page] Default Menu Item choose [Recent topics] different

Hi ~
In main menu , there is a Menu Item Alias that Menu Item  is Forum
And Forum's setting > [Menu Item Type]：Home Page / [Default Menu Item]：Recent topics
[Recent topics]  I just choose to show "Forum1" category.

However, in the front site, when I click "kunena menu", it will show "Forum1" + "Forum2" + "Forum3"
and I click "Recent topics" , it will show "Forum1" correctly.
"kunena menu" should equal "Recent topics" , just show "Forum1", but it's not

Please help~ thanks

Your setting is contrary. You have selected in the configuration:
Category List in Recent Topics = Show all Categories 
and in the menu item Recent Topics:
Show Forum 1

My setting is the same like what you say~ (the pictures are from my first post)
configuration:
Category List in Recent Topics = Show all Categories 
 

in the menu item Recent Topics:
Show Forum 1
 

My question is the menu choose to show Kunena Home Page
and home page's default menu item is Recent topics
 

Why Home Page doesn't just show Forum1 like Recent topics ?
 
 

My setting is the same like what you say~ (the pictures are from my first post)

Yes, but I also wrote that this is contrary. You must set for both the same.
If you want additional a menu item where you can see all topics, then make a duplicate of the menu item Recent Topics and choose all categories.

Because there are many sets of kunena forums in my site, so I don't understand how to "set for both the same"I change my question , I hope my site's forum like below, how could I set it?  Thanks! 

If I understand correctly, when you click on "Kunena Menu" you only want to display the latest topics from forum 1. I'm right? So you need this setting also in the configuration. That's I meant with "You must set for both the same".