Data validation to set minimum value zero and goal seek by vba makes negative value

[Azzee]

Hi! I am new to the forum and vba beginner,

I have used data validation to set a cell value minimum to zero, it is not allowing to input any negative values and it is working fine.
However, I have made a goal seek by vba and made the same cell as changing cell. When I run the vba it gives negative values also regardless of the data validation restriction.

Any suggestion to set minimum value to zero for the same cell by vba as data validation does not work on above situation?