I just made a clean 1.7.2 install. and made 1 Chinese group. When you click inside of group, Chinese text become gibberish.
<p style="margin-bottom: 4px; padding: 0px; border: 0px; outline: 0px; vertical-align: baseline; background-color: rgb(255, 255, 255); font-family: Tahoma, 'Lucida Grande', Verdana;"><span style="color: rgb(51, 51, 51); line-height: 16.25px;">凱帝推廣團隊</span></p>
I don't see any styles. Try to create a group with the English content click in the Description fields and provide screenshot of the ow_groups_group table again.