The plugin can be used to remove all the existing content and install a new version from scratch.
Please do the reset and reply with temporary wp-admin access here. We will help you with the import.
I have checked the same demo on our test site and found no issue it is working just fine check this video for a better reference: https://streamable.com/nbm33c
There is no image issue.
There is no menu issue.
There is no slider issue.
All works perfectly fine.
The issue is only at your end. The theme has no issue it works ok.
I can show you all these things and how these are set on the site.
