yes you are right
8,23 is the summe of the shipping price and the base product price without TAX but there in that case must be
the final price ( 2 € ) without tax + shipping without tax
where do you see 9,90 there must be 6,90
because for the customers this invoice it's really not clear and it seems that this 1,10 it's the TAX of 8,23 but it's not so , are the TAX of 5.79 ( 6.90 without 19 % )
IF THERE IS NO DISCOUNT it's all right , the problem born with discount .
i hope you can help me
Thanks
best regards.