Hi Sreeraj,
Thank you for contacting Syncfusion support.
We have checked with the provided details, both comment and reply comments are visible while loading the downloaded PDF document with annotation comments in the PDF Viewer. We have shared the screenshot for your reference which can be downloaded from the below link.
We suspect that the reported issue “reply comments are not shown in browser (chrome)” is due to reply comments are not supported in the chrome PDF editor. So, the reported issue may occur. But we can’t replicate the same issue in our PDF Viewer and Adobe viewer.
Regards,
Vasugi.