Hello Andreea. I've created a ticket with our Support Team so we can look into this reports further. 

From my cursory review, I can see that the default sorting of a report is not copied exactly when it is exported. For example, if you navigate to the Tickets Overview Trend report and export the report, the CSV will be sorted ascending (8/18 - 8/24), though the interface will be sorted descending (8/24 - 8/18). If you modify any of the sorting options and generate a new report in the interface, the export matches exactly. We'll see what else can be found in this area. 

On the ticket, I'd also ask that you provide more information on which Overview Trend report is inaccurately reporting the time so we can review this further. 

Thank you,