Export PDF to Chinese missing characters

I am using the Adobe Acrobat export PDF utility.  I am using the web app which is in

documentcloud.adobe.com

I am paid subscriber to the service which allows me to upload a Chinese PDF and convert this to a word document.  This used to work perfectly.  I always make sure I export to the traditional Chinese.

Lately the conversion utility only export half of the charactures.  Below is a screen shot.  The file on the left is the original PDF.  The right is the web app export.  As you can see lots of missing characters.  I contact support with no avail.  They recommended to post it here.  I tried multiply files including those which used to work.

Is this the right way to get help from adobe?