Tax Explanation codes for EU

in Production

User AR has an Invoice and want to add it in JDE from Dutch EU Customer 

Gross amount 17968.50 EUR 

21% Tax              3118.50 EUR expecting

Using Tax Rate area DEP02721 IN and OUT and Tax explanation code V the Posting Program calculates Tax 3.773,39 of In and out instead of 3118.50  ?

In P4008 DEP02721

21 +  GL offset XX 

21 -   GL offset VC

=000

Tested the issue Test Environment: 

1-Tax rate area DER02721 with V and Tax is 3.773,39 when Posted.

2-Add new Tax rate of 21% Standard and Tax is 3.118,50- as expected.

   P4008

   21+ GL-offset

=21 +

Any thoughts why it is different figures 3.773,39 versus 3.118,50?

Thanks

Saleem