Perfomance maximum but still not working

I would suggest you add a
Print to console puzzle above you print performance puzzle with say something like “ performance good” conversely ilyou could add one to poor performance section of the check performance puzzle but change the text to “performance bad”

This will let you know if the check performance puzzle is either good or bad.

I would further suggest you change the color of you replacement texture as a test so you can visually tell if the material changed color.

I do t think you logic is bad… I think you are not able to tell the difference visually given you screen size and resolution perhaps and changing colors will confirm the logic is working or not.