I tried hunting for this first before posting. I built UE4.26.2 from releases on github for linux. On attempting to play around in material editor I noticed the shader base pass and dynamic readouts from the stats panel remained at 0, despite what I added or took away from the material I was constructing.
Thinking it might be an error in building I attempted a fresh build of the engine again (4.26.2), and again it produced the same issue.
After searching online for an answer and not finding much I then decided to try the master branch (11th May 2021) in case this was something that has been fixed already and after building, I found the stats for base shader and dynamic shader missing completely.
I tried a couple of default materials and found them missing the shader stats also.
Am I missing a new setting somewhere?
My system is running Arch Linux / Plasma-KDE