Sorting is not reset after loading in a saved report without sorting specified

Hi All,
 
We are migrating our flexmonster version to the latest and we noticed a weird behaviour with sorting.
 
Steps to reproduce:
 

1. Go to your demo page https://www.flexmonster.com/demos/js/pivot-table/
2. Remove Order Date from the columns axis and click Apply.
3. Open browser console and run the following command to reset sorting

flexmonster.sortValues("columns", "unsorted");

    4. Click Save report. A JSON file with the report configuration should be saved to your downloads folder. The report should NOT contain any sorting information because we reset it in previous step.
    5. Click Total Sum of Price column to sort it. Sort type doesn't matter. The data should be sorted now.
    6. Click Open -> Local report and select the report saved in step #4 without any sorting.
 
Actual result:
The sorting done in step #5 is preserved although we upload a report without any sorting information.
 
Expected result:
The sorting should be reset because we upload a report with no sorting settings and existing sorting should be overwritten
 
Please note, it used to work fine in 2.3 version and we believe it was a proper behaviour. Is it a bug or is it by design now?