The "Move all non-imported files..." function does not move sub-directories or their contents. Also, sometimes there will be imported files in the directory that you weren't aware were imported. Those imported files also will not be moved.
To do what you want use the Explorer function found in the left Navigation Bar under "Drive & Devices > Explorer".
At the top of that function, select Mode: "Only files in library", and leave the "Show Files In Subfolders" box unchecked.
Drill down to where the music files that you want to move are located.
Now change the Mode at the top to "All files", and tick the "Show Files In Subfolders" checkbox.
Make sure that the destination location you want to move the directory tree to is visible in the MC Explorer tool.
Then click on the root directory of all the files and sub-directories you want to move, then Drag & Drop that directory to the location you want the directory tree moved to, release the mouse button and select "Move" from the popup menu.
MC will move everything in that directory tree and update the Library correctly.
TEST THIS FEATURE CAREFULLY ON A SMALL NUMBER OF FILES BEFORE DOING MASS CHANGES.
MAKE SURE THAT YOU HAVE BACKUPS OF THE DIRECTORY TREE YOU TEST ON BEFORE YOU START, INCASE SOMETHING GOES WRONG.
This is a
very powerful tool and how it works isn't always completely obvious. So while you are learning, be prepared to repair any damage done. If you follow the simple sequence above though it should work fine.
Search the forum if you want to understand more about how this function works. It has been discussed in detail. I don't think there is anything in the Wiki.
Note:
This should be done only on a standalone version of MC or a MC Server version, where MC is implemented in a Client-Server arrangement. It can not be done on a MC Client when implemented in a Client-Server arrangement.
Basically, this sort of file maintenance must be done where MC has direct access to the files, either on a local disk drive, or a connected external drive, or a NAS drive.
It can be done from a MC Client via the Network tree in the Explorer function, if you have direct access to the files via a Network Share, but I wouldn't do it that way. It would be very slow to both navigate the views and perform the move.