Strip mining with a stone pickaxe, and suddenly mine some infested stone blocks. In 21w18a, it was changed so they break slower than regular stone. Either it hasn't been added to the datapack or it's a bug
MC-225555
Infested Stone Blocks break instantly in 21w19a datapack
Resolved
Cannot Reproduce
0
I am unable to reproduce this issue in 21w19a. Infested stone takes half of the time to mine than regular stone.