Zend certified PHP/Magento developer

Magento 2 Reports are not accurate

The report generated by Magento 2 (backend > reports > sales > coupons) does not show exact values.
For eg the following order was placed with discount -10CHF
order totals from backend

However, on the coupon report on the same store scope does not show the same
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*All the totals are tax inclusive including the shipping cost.

The issue is similar with other reports, for eg the order report also has incorrect totals.
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Do you guys have experienced this issue ? Any help would be appreciated.