Why is there a discrepancy in tax calculation between checkout and draft orders?

[Mmnederland]

Hello dear Shopify people, 

Backstory: We work with Shopify Markets, and use product overwrites to assign the proper TAX rule for each country. In this example Dutch and German, resp. 9% and 7%.  

I've consulted a pretty amount of documentation from Shopify:

https://help.shopify.com/nl/manual/markets/pricing/dynamic-tax-inclusive-pricing#dynamische-prijzen-...

https://help.shopify.com/nl/manual/taxes/eu/eu-tax-manage#creating-a-product-tax-override 

https://help.shopify.com/nl/manual/taxes/location 

and so on..

Who can explain this to me a laymen terms what happens here:

CHECKOUT:

Product A has a selling price in the Netherlands of 27,70 EUR (incl. 9% VAT) base Price = EUR 27,70/1,09 =  25,4128 [so far Shopify is correct). 

Product A has a selling price in Germany of 27,19 EUR (incl. 7% VAT) base Price = EUR 25,4128 * 1.07  =  27,1916 [ but in CHECKOUT Shopify says it's  EUR 27,24. How??

BACKEND:

When making a DRAFT order:

Product A has a selling price in the Netherlands of 27,70 EUR (incl. 9% VAT) base Price = EUR 27,70/1,09 =  25,4128 [so far Shopify is correct]. 

Product A has a selling price in Germany of 27,19 EUR (incl. 7% VAT) base Price = EUR 25,4128 * 1.07  =  27,1916 [ DRAFT order Shopify says it's  still EUR 27,70, but they subtract it the other way around (EUR 1,81). How??

Looking forward to constructive advise