Recalculated (reduced) social security contribution in Dexxter

For the quarter in which I started as an entrepreneur in my main occupation, I received on a regularisation notice from my business desk Xerius. The initially planned contribution was recalculated and reduced. Now I was wondering if there is a way to include that reduced contribution in the calculation of Dexxter’s social security contributions?

I have already entered the social security contribution for that quarter as an expense, under the category ‘social security contributions’, with the reduced amount. However, Dexxter does not know that I received a reduction, so the ‘social security contributions’ webpage states that I still owe a certain amount. I suspect that this is not a big deal, but if anyone can tell me more about this (about the question of whether it is a big deal, or whether I can adjust it), that would be welcome.