Drag threaded conversation to folder

If I import a conversation thread from email to my global inbox, I usually want to move it off into another folder/db… I note that nothing happens when I drag the threaded conversation (its closed so I just have the icon with the two handles); but if I open the conversation and drag the msgs within there it works fine.

It would be nice to be able to drag the top level conversation.

Do you use Apple Mail? Which version of macOS? A simple test was successful in both cases (opened/closed conversation).

I’m running mojave 10.14.6; dt3b5; apple email;
I may not have been specific enough.
In DT3b5 I have done an import mailbox via the plugin.
I am viewing the emails in DT3, alternate view is set as default and sort=threaded.
dt3 prefs has “import complete conversations” enabled, along with “group conversation threads”
So in this view I have conversations.
Here is example:

First I assume I shouldnt be grouping conversations and showing threads since it seems things are shown twice.
What I was referring to was that I couldnt take the top level item and drag it into a different group. Nothing happens…

Dragging the group in there to another group works fine.

However if its just the conversation view I cant drag that top level blue icon to another group and have it pick up all emails under there…
I removed the group above, so now I have this, and I tried dragging the blue icon:

I’m fine if thats the way it was supposed to work; I had expected to be able to drag it.

Usage of both is indeed not recommended.

Threads can’t be dragged (yet) as the threads aren’t real items.