It works for me in in Theater View.
For debug purposes try running mc28.exe /mcc 23020,0 this will display the 'Importing Media' when running and 'Import summary' on completion.
Also try setting up a local test folder, include it in your 'auto import' rules and place a test audio file or some such in it to see if gets imported.
You might want to switch off 'Run auto-import in background' while you are testing your batch file as well.
EDIT: It occurs to me that this could be anti-virus related, are you running something other than Windows Security? See also the sticky 'Taming Windows Defender on Windows 10' at the top of this board.
I think it would be a well reported issue by other users if auto-import wasn't working in Theater View.
I also think you probably need to address the issue of why auto-import isn't working normally, see the wiki page here:
https://wiki.jriver.com/index.php/Auto-Import.
It may be your network storage does not support file system events which reduces the frequency with which auto-import will run in which case using a batch file is a good work-around.