How do i change to absolute dimension instead of addition?

Hi all,

I am currently using shapr3d on Mac. I recall that when changing dimension of extrusion, it was always to change the absolute dimension, however idk is it some settings i did or updates that it become addition method now (see attached). This meant if i want to reduce the thickness or extrusion, i have to manually calculate the difference and enter a negative value instead of the absolute thickness i want. Help?