While analyzing the reported scenario, The Chinese text is written in Unicode script. However,
in the absence of font information, the Unicode text may not display correctly
on viewers.
When it comes to annotation comments, certain browsers
such as Chrome and Edge may not support annotation parsing or annotation comment
popup parsing. If the browser does support annotation parsing and rendering,
then you won't encounter this issue.
For instance, we discovered that Mozilla Firefox viewer
does support annotation parsing and rendering, and it shows annotation and comment
information correctly. We have attached a screenshot for your reference.
Furthermore, you can replicate this problem even without
using our Syncfusion library. For instance, if you add an annotation in Adobe
Reader that includes Chinese text comments and then view it in Chrome browser,
you will still encounter the same issue. Therefore, this is not an issue
arising from the Syncfusion library.