Kmail 5.4.3 ignores Maildir DB in ~/mail

[Maurice]

When started kmail (5.4.3) appears to ignore the 'maildir' 
DB in ~/mail, instead showing an empty default minimal local-folder 
structure.
 
Steps to Reproduce:

1. Start kmail

2. Note empty folder structure on left. (Input, Sent etc)

3. Note that in Settings/Accounts/Local folders, 'Modify' shows that
   '/home/user/mail' is set as 'folder containing the maildir info' and 
    "The selected path is a valid Maildir."

4. 'Update folder' has no effect.

  Help!

-- 
/\/\aurice   (Using Mageia-6RC)