I am on a 2020 Macbook Air running Big Sur 11.7.1, and Microsoft Office for Mac 16.77. In the last year or so, many (but not all) unicode Devanagari fonts has stopped functioning properly in Office (e.g. Word, Outlook). Conjunct glyphs are decomposed with virama ("vowel-killer") under each part of the consonant cluster. This is happening with many commonly used Devanagari fonts including Arial Unicode, Devanagari MT, Sanskrit 2020, Mangal, and others (though a few still seem to work).
Even if I copy Devanagari text that is properly displayed in a non-Microsoft program such as TextEdit or LibreOffice, when I paste it into Word or Outlook, it is displayed incorrectly.
This is a major step backward in functionality of Microsoft products with Unicode. What is the problem. Can it be fixed?