Hi Kuldeep Biswal,
Reviewing through your description I would recommend submitting a case in your customer group as a next step for investigation by the next available member of our support team. When doing so if you couple provide the following it should assist with their investigation:
1. Is this occurring for all draft contents, or is it limited to a specific content type (blogpost/document)?
2. Are all users seeing the behavior or does it appear to be limited to a specific user/group of users?
3. A screenshot of any error you are seeing in the UI