This page came up with raw mathtex, then I saw a
"math rendering xx%"
counter at bottom right, then 15 seconds later I had the page:
https://en.wikipedia.org/wiki/Noether's_theorem
I admit this sort of page would make a good stress test ...
Possibly related: the Math reference desk was rendering
impossibly slowly (to the point of timeouts and WMF error pages)
a few days ago. Discussion at: