I need some help with setting the default value for a DropDown box in PowerApps

I have a DropDown in my App which writes back to DWH
AllowedValues for the DataCard "Car Seats" are [999;0;1;2;3]
In an early version of this PowerApp Car Seats would show 999 as the choosen value (a.k.a DefaultValue) but now it shows 1.
Changing Default for DataCard is not an option because i dont want to get the last write back value in the DataCard.
How do i resolve this?