It is hard to determine the main point of the issue and its reason. Could you please perform the following actions:
1. If possible, export all cases started from midnight of the day before yesterday by using native Salesforce means or create a screenshot with all records. Specify all the filters as you do on the previous screenshot in Salesforce. It is better to create an export in the noon.
If you are going to create a screenshot, then attach it to this post so that it had a readable resolution.
If you are going to make an export, then send it to us via email support at devart dot com.
2. Run the export (64856) and import (60664) packages one after another immediately after performing export from Salesforce or making the screenshot. Send us the result of the export package via email support at devart dot com.