@andrey.gubal Meanwhile we tried the above html to docx conversion with Words Cloud API and its working. Here is the curl,
curl --location --request PUT 'https://api.aspose.cloud/v4.0/words/convert?format=docx' \
--header 'Authorization: Bearer token' \
--form 'Document=@"/path/to/input.html"'
Could you confirm if we can rely on this API for this conversion? This will unblock our development for now. We initially thought html to docx can be achieved with HTML cloud only. Please provide your thoughts.