Import/Export demo

Hi,

We are a team of developers who are beginning to publish our theme on Themeforest. We are facing an issue in presenting the demo of our theme and wanted to seek your help.

Whenever we try to export our theme demo content and import it somewhere else, the pictures don’t go in their correct position as before. For example, the picture of a blog post goes to portfolio and vice versa.
The image’s IDs in imported demo is not the same as ID’s in the exported demo. For example, Logo’s ID was 6 in exported demo but it was appeared in imported demo with number 21.
We use Wpbakery for page building and Redux Framework for theme option.

Is there a plugin or tool we can use to fix our problem or should we follow certain criteria?