Ok, I could finally review your configuration, and it was due to the number formatting of (1.002,00) triggering a rounding bug with the setting of taxes included.
Bug is now fixed in latest nightly:
forge.joomlapolis.com/issues/7952
Please upgrade (backup site first as usual) and confirm if it is fixed for you.
EDIT: Please also fix your setting of VAT: it should not be 15.96639% but 19% if your tax rate is 19%. CBSubs computes correctly the taxes-excluded amount for taxes-included prices using the VAT rate.