Material changes only manifest positively, not negatively

hey so - im changing, its like a constant, in a formula for a material
its not my material its stuff off marketplace , but its epic
wait no this was in starter content

so im modiying a lot of the blueprint
parts

and i modify a thing and it changes nothing.
and i modify a thing and it changes nothing.
i skip this because i know the intellect level of people, generally.

then this, im incrementing a variable
its a straight-shot variable

and it shows up immediately in my viewport
sometimes i have to save
its kind of awkward, i havent been tracking it - yet.

when i decrement on the variable nothing ever ever ever changes

i cant follow it 100% but im changing the material, saving, building, and the material does not “adapt”
in the screen

i cant track it enough to be specific, i think its that it does not recognize an object change on a decrement