I do not observe such behavior on the Nisarg theme on my blog. The sidebar is intact whenever I insert block images within the text itself or when adding a blog post picture. Not really sure what to say other than to pay attention to options within the theme itself when setting it up. Feel free to check my blog for reference. http://www.ajourney.com (click access content)
I figured this one out by modifying CCS in child theme. Thanks
This has been resolved so never mind
